Description
The telecommunications industry contributes around 45% of the country's Gross Domestic Product (GDP) and might therefore be considered of relatively minor importance to the country. However, its own GDP does not reflect the wider importance that telecommunications plays in the economic and social wellbeing of the country.
1
Telecommunications Networks – a vital
part of the Critical National Infrastructure
Version 1.1
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Telecommunications Networks – A Vital Part of the Critical
National Infrastructure
CONTENTS
page no
Executive Summary 3
Introduction 4
Chapter 1: The Nature of UK Telecommunications Networks Describes the
nature of the UK telecommunications networks. If you are familiar with telecommunications,
you may want to skip straight to Chapter 2. 5
Chapter 2: Types of Telecommunications Companies in the UK Describes
the commercial environment and the wide variety of telecommunications providers in the
market, which collectively make up the ‘UK Network’. 14
Chapter 3: Threats to Continuity of Service Describes the wide range of threats
to the continuity of service over the UK networks. 16
Chapter 4: Resilience measures taken by telecommunications
companies Covers the typical measures taken by the network companies to meet the
challenges posed by these threats and mentions some of the remaining residual problems.
18
Chapter 5: Statutory provisions concerning telecommunications
resilience Telecommunications is now a competitive private sector activity, there are a
range of statutory provisions that touch on the government’s ability to assure the resilience of
the UK networks and these are described in Chapter 5.
21
Chapter 6: Roles of Government departments, the regulator and other
agencies Sets out the roles and responsibilities of the various government
departments, the regulator (Ofcom) and other agencies, describing how in practice they work
together as an extended team in assuring resilience. 27
Chapter 7: Emergency Plans and response measures Covers the present
arrangements in the telecommunications sector which ensure that industry and government
work effectively together in emergencies and other times of stress. 29
Annex 1: Typical Smaller Network 30
Annex 2: Definition and List of Category Two Responders 31
Glossary 32
3
Executive Summary
This document explains how the UK’s telecommunications networks are a
vital component of the country’s Critical National Infrastructure, the ways in
which resilience in both networks and services is achieved and the roles of
government and other agencies in the maintenance of this capability.
This document contains information for all those who need to have a basic
understanding of the electronic communications environment, ranging from
Senior Information Risk Owners (SIRO’s), Business Continuity Managers and
Emergency Planners in central, regional and local government as well as
businesses part of the CNI.
Recently, telecommunications has been going through radical change. Many
of these changes are being influenced by the convergence of technologies,
particularly computers and telecommunications, as well as broadcast, the
internet and other information services. This convergence of technologies, has
led to the era of the Information Society. It has always been acknowledged
that telecommunications is essential for the economic, social and cultural
development of society, but that requirement has become even more evident
as the Information Age is increasingly recognised as the future of all societies.
From a regulatory perspective, the European Directives are encouraging a
free market approach and the UK regulator Ofcom recognises that this
approach will bring new services, technologies and opportunities for increased
innovation and potential for competition leading to reduced costs.
There are regulatory obligations on electronic communications providers in
relation to resilience and emergency planning? for the wider market there are
duties and powers provided through a number of different pieces of
legislation. However, the industry has shown its ability to work with
government on a voluntary basis to improve emergency planning
arrangements. These plans are well developed and regularly tested.
Most central and local government telecommunications systems are today
provided by the industry, and there is a requirement for customers of these
services to have some form of understanding of how the UK Telecom Network
functions. This document aims to fulfil this need.
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Introduction
The telecommunications industry contributes around 45% of the country’s
Gross Domestic Product (GDP) and might therefore be considered of
relatively minor importance to the country.
However, its own GDP does not reflect the wider importance that
telecommunications plays in the economic and social wellbeing of the
country. Almost every UK business is dependent on telecommunications to
transact business, as is every branch of central and local government and
related public bodies.
The social life of the country is highly dependent on telecommunications too,
be it the capability to broadcast TV to every home, for friends to ‘text’ one
another to arrange their appointments or for anyone to summon the
emergency services via 999. The defence and security of the nation is also
highly dependent on reliable communications. Telecommunications therefore
has a ‘multiplier’ effect and its importance to the overall continuity of life and
the democratic tradition of this country is immense. Such is its importance that
governments have recognised that the issue often transcends the narrower
commercial interests of the companies who supply services and therefore
government has some duty to assure the resilience of the country’s
telecommunications systems and services.
For many years prior to 1984, telecommunications was run by the government
as a statutory monopoly. It could ensure that the General Post Office (GPO)
took due account of the requirement to serve the country in an appropriate
way, with adequate provision for the resilience of the system. Since 1984, not
only has telecommunications been provided in an increasingly competitive
commercial environment, but also a much wider range of services has
become available – and come to be relied on – such as mobile phones and
the Internet. Government now has to proceed partly based on supporting
statutes, but to a large extent by voluntary cooperation by the industry.
Critical National Infrastructure
The importance of telecommunications resilience is reflected in the fact that
government has identified telecommunications as one of the top 10 sectors
deemed to be part of the ‘Critical National Infrastructure’ (CNI). The
government views the CNI as those assets, services and systems that support
the economic, political and social life of the UK whose importance is such that
any entire or partial loss or compromise could:
· cause large scale loss of life
· have a serious impact on the national economy
· have other grave social consequences for the community
· be of immediate concern to the national government
Telecommunications fits with each of these 4 points.
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Chapter 1
The nature of the UK’s telecommunications networks
1. Before explaining the threats to the UK telecommunications capability
and the means of mitigating those risks, it is important to understand
the nature of telecommunications networks and the kinds of company
that now provide those networks and/or the services running over
them. Those familiar with telecommunications networks may wish to
skip to Chapter 2.
2. The fundamental principle of telecommunications is the ability to
transmit information over a distance. Transmission systems comprise
three elements:
· A Transmitter?
· A Transmission Medium? and
· A Receiver
3. The Transmitter converts the information into a form of energy
appropriate to the Transmission Medium in use and injects that energy
into the Transmission Medium. The Transmission Medium conveys the
energy over a path to the Receiver. The Receiver converts the
received energy into a form suitable for use at the receiving location,
thereby creating a distant replica of the original information. Although
TV signals are broadcast oneway out towards viewers, most
transmission systems are bidirectional, allowing conversation and
interaction between 2, or sometimes more, parties.
4. All forms of telecommunications use different types of electromagnetic
energy and the principle types of transmission media are:
· Electrical signals over metallic wires?
· Radio waves through the air and space?
· Light signals through optical fibres
5. All of these are different forms of electromagnetic energy, but differ
widely in the frequencies of the signals used. The list is not exhaustive,
for example, low frequency short range magnetic coupling is used for
systems like hearing aid loops for the hard of hearing and infrared light
is used to communicate between our TVs and their remote controls.
Though these technologies aren’t used for public networks, they are all
forms of telecommunication.
6. In order to understand the role that individual transmission systems
play within the telecommunications network, it is useful to describe the
overall structure and use of the network.
7. A telecommunications network comprises two main parts:
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· The core network, comprising a large number of buildings (mostly
telephone exchanges) connected together by transmission systems?
· The local or access network comprising copper and some fibre
cables connecting individual customer premises into the core
network at the local telephone exchange building.
Although BT’s network is the largest and serves the entire country’
each telecommunications network company has its own core network
and its own access network,. However, it is impractical for other
competing operators to completely replicate the scale of BT’s network,
so they may rely on acquiring capacity or facilities from BT or other
operators in order to construct their desired network. So a competing
operator may construct its own small fibre network connecting the
major cities and rely on other means to connect to areas and
customers ‘offnetwork’. Many operators start by constructing a ‘figure
of 8’ network connecting, typically, London, Bristol, Birmingham,
Manchester and Leeds? paralleling the early deployment of both canals
in the 18
th
century and railways in the 19
th
century.
Figure 1: A small core network
The core network
8. In the core network, the most usual transmission medium is optical
fibre, which comprises a length of very pure glass, about the thickness
of a human hair, capable of carrying light signals over a considerable
distance (100s of kms). Other transmission media are sometimes used,
such as microwave radio or satellites. In the case of optical fibre, the
transmitter consists of a laser which generates a strong pure light
source, while the receiver consists of a light detector which indicates
the presence or absence of light signals. The fibre optic system works
by rapidly switching the light source on and off, many millions of times
a second, thereby producing a system capable of conveying a digital
information stream, that is, a stream of signals representing the binary
states 1 and 0 (on/off). Information, be it voice, video or data is coded
into a digital form prior to transmission. Individual fibre strands are
protected by a plastic sheath and then bundled together in groups of
between typically 24 and 96 to form a fibre cable, with its own outer
A core network of
exchanges
connected by a
mesh of fibre optic
cables
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sheath and strengthening core. Each strand is isolated from the others
and capable of separate use.
9. Sometimes the network of cables is organised into sets of discrete
hierarchical rings and sometimes in a less structured mesh. At the ends
of the fibre systems, including those at points round the ring structures,
the light signals are converted back into electrical signals and
connected to a multiplexer. The function of the multiplexer is to allow
many separate individual circuits (which may be carrying individual
telephone calls or private circuits) to share the capacity provided by the
individual fibre. This is possible because the fibre cable may provide
for, say, 10 Gigabits per second (Gbit/s) to be conveyed, whereas a
single telephone call only occupies 64kbit/s. Such a system could
therefore convey over 150,000 separate simultaneous calls. This
capacity sharing is achieved by the technique of Time Division
Multiplexing, whereby each call or circuit is allowed in turn to transmit 8
bits on the fibre every 125 microseconds.
10. The BT core network comprises around 5500 telephone exchanges
connected together by fibre optic systems. This extensive network then
connects to around 350 buildings where regional and trunk networks
are focussed.
11. Other core networks are much smaller and may only use about 540
exchanges and a few hundred ‘points of presence’ where connection
from customers is made via their own access circuits or by renting
circuits from other operators. A diagram of a typical smaller network is
shown at Annex 1. Such smaller networks often reflect the company’s
focus on business customers in major cities.
The local or access network
12. The purpose of the local or access network is to connect individual
customers to the nearest suitable point on the corer network, often the
local telephone exchange. There are three broad types of access
network:
a. BT’s network, covering virtually every home and office in the
country and largely made up of copper cables, but with fibre
links for serving larger businesses?
b. Competitor networks focussing on business customers, almost
exclusively comprising fibre cables, with some use of microwave
radio?
c. The Cable TV company networks, which also provide telephony
and other telecom services, which comprise a hybrid network of
fibre cables with final delivery via copper coaxial or pair cables.
13. The BT access network mainly comprises copper cables stretching
from the telephone exchange out to individual homes and offices. It is
structured in a ‘tree and branch’ manner, with very large cables, of up
to 4800 copper pairs, extending from the exchange Main Distribution
Frame (MDF) through underground ducts, to roadside cabinets, known
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as Primary Crossconnect Points (PCPs). At the PCP, individual copper
pairs are crossconnected to others in smaller cables that then radiate
out to many individual Distribution Points (DPs). A DP will typically be
sited at the top of a telephone pole or within larger office buildings.
From the DP, individual copper pairs are delivered to each home, in the
case of a telephone pole sited DP, this will be via a dropwire, strung
between the pole and the home. The pair of copper wires is often
called the copper loop. The figures below show how a customer’s
home is connected to the network and the overall topology of the
access network.
Figure 2: Typical layout of a local access network
14. The outcome of this structure is to provide for every customer a pair of
copper wires that act as a single pair of electrical conductors from their
abode to the telephone exchange building, where they are terminated
on the Main Distribution Frame (MDF). From there, the pairs are
connected either to the telephone exchange equipment or to other
telecommunications apparatus provided for other types of service, such
as data services or private circuits.
15. In the case of large office buildings which have large demands for
telecommunication services, fibre cables may be provided instead of
copper, as the revenue may justify the higher capital expenditure.
16. An important distinction between the core network and the access
network is that the former comprises mainly high capacity transmission
systems shared across many types of use, while the latter is mainly low
capacity wires, each dedicated to a single customer.
17. The other business focussed companies (e.g. Cable & Wireless,
Energis, VERIZON BUSINESS, Thus, COLT, Affiniti, Your
Underground cables are carried in
earthenware ducts (4, 6, or 12 tube)
laid in trenches. However, recent
construction will often use single
plastic tubes, as nonBT providers
use.
MDF
Exchange
Cable
Chamber
Distribution Pole
Street
Cabinet or
Primary
Cross
Connect
Point (PCP)
48 pair
6004800 pair
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Communications) may have extensive ownbuild access fibre networks
in London and other major cities, but typically will otherwise provide
their own fibre access links to customers only where the demand
justifies the bespoke construction. Unlike the copper pairs used to
deliver a single telephone line, these fibre cables, like those used in
core networks, can handle many separate circuits and services and
generate much higher revenues, often for corporate data services
rather than plain telephony.
18. In March 2006 ntl and Telewest completed a merger creating the UK's
largest residential broadband communications company delivering both
television, broadband and telephony to about 50% of UK homes
(though takeup is less than this, around 12%). Their access networks
use a combination of fibre to the street cabinet then a mixture of coaxial
cable to carry TV and copper pairs for telephony from the cabinet to the
home.
How a telephone call is connected
19. The following brief description is given of how a telephone call is
established..
20. The call is initiated by the caller lifting the handset which causes
current to flow round the copper pair loop and this is detected at the
telephone exchange. The wanted number is dialled and the exchange
analyses the dialled digits to determine which direction the call is to be
routed. The call will be extended by the exchange providing a cross
connection, for the duration of the call, from the local copper loop to a
digital channel amongst many on a multiplexed fibre cable connected
to the next exchange. Successive exchanges repeat the routing until
the call reaches the local exchange of the wanted customer, where it
will be connected to that customer’s local copper loop and the bell
rung. Different calls will take different paths through the network, but
the routing through the local access network is always fixed, as each
customer has a dedicated copper loop from his premises to a local
exchange.
Final
Distribution
Point
Video
Amplifiers
Coax
Street
Mux in
cabinet
Fibre
TV
Cable TV HeadEnd & Exchange
Siamese cable
(coax plus 2
copper pairs)
Copper pairs
TV LE
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Figure 5: Telephone network architecture
21. In practice, the network is a little more complicated than this simple
description. The local exchange to which customers are connected
actually comprises two parts, a remote concentrator with limited
functionality to which the copper loops are connected in over 5000
towns and villages and a more complex computercontrolled ‘host’
exchange located in the nearest principal town. The ~740 local
exchanges are connected via a network of over 100 trunk or tandem
exchanges located in around 80 major locations across the country.
22. Some operator’s networks have far fewer telephone exchanges and in
general do not use remote concentrators. The smallest companies
have only a single switch ‘layer’. Customers are connected via fibre or
hybrid fibre/copper networks. However, the principle of stage by stage
call establishment is the same.
Private Circuits
23. As well as providing a telephone network, the transmission network can
be used to provide business customers with Private Circuits. A Private
Circuit, unlike a telephone call, is not designed to connect from one
point to any other? rather it provides a permanent connection between
two specific end points, such as two branch offices. A private circuit is
formed by connecting, on a semipermanent basis, the local access
circuit at one end to a path through the core network of multiplexed
fibre cables until it reaches the distant exchange building, where it will
be connected to the local access circuit of the farend point. Unlike a
telephone call which disconnects when the caller finishes the call, this
connection remains held all the time, as long as the customer
continues to rent the Private Circuit service. However, like a telephone
call connection, while the routing through the access network is fixed,
the routing through the core network can vary and may rapidly change
in response to faults in the network or other planned rearrangements.
This rerouting is performed by using electronic crossconnect
equipments situated in exchange buildings. Furthermore, the Private
Approx 100+ tandem
exchanges in about 80
major locations
About 5000
concentrators in
almost every town
and village
About 740 local
exchange ‘host’
units in about 300
buildings
11
Circuit will be occupying capacity on the core network of multiplexed
cables and sharing these cables with many thousands of other Private
Circuits or channels used in the telephone network.
Figure 6: Typical arrangement and routing of a Private Circuit
Supporting others’ infrastructure needs
24. Because Private Circuits provide transparent capacity between end
points, a telephone company may rent a Private Circuit service from
another telephone company in order to provide the underlying
transmission it needs to build its own network. For example, a mobile
telephone company will rent Private Circuits in order to connect its
radio base stations to its network of exchanges.
25. Alternatively, a company may acquire the right to use individual fibre
strands in another company’s cable. This is known as a ‘dark fibre’
lease.
26. Hence, many telecommunications networks are dependent on others
and resilience may depend on the performance of several operators.
Mobile Networks
27. Mobile phone networks represent a special type of network which
shares many attributes of fixed networks but several critical differences.
28. Like a fixed network, the core network comprises a network of
telephone exchanges connected by fibreoptic cables. However the
access network is quite different, comprising a set of Base Station
Controllers and the many Base Stations themselves (the antenna sites)
which then communicate with handsets using radio. Additionally, the
core network has several databases, known as Location Registers
which keep track of the location of handsets as they move around.
Dedicated
link to
customer
through
the access
network
Dedicated
link to
customer
through
the access
network
Route (in red) over which the private
circuit is being carried at a given
time, sharing capacity with many
other circuits
Black (dashed) links show
other paths that the circuit
might occupy when other
links fail or require
maintenance
Electronic multiplexers
which crossconnect
individual circuits from
one link to another
Core Network
12
Figure 7: Typical mobile network
Internet
29. The Internet represents the other dominant form of network in use
today. Since the 1970s there have been many types of data network
deployed using a wide range of technologies and acronyms (e.g. X25,
Frame Relay, ATM, SMDS, FDDI… ). However, the development of the
Internet, especially since its commercial exploitation from the early
1990s, has been dramatic and now IP (Internet Protocol) is not only the
data network protocol of choice, but is likely to become the technology
over which almost all forms of future network are built, including the
traditional public telephone network.
30. It is important therefore to distinguish between the public Internet,
which is a ‘network of networks’, all interconnecting with the same set
of protocols and the use of IP technology to build entirely private
networks (‘intranets’) and other managed IP networks which might be
used for the provision of more robust public telephone services.
MSC MSC
BSC
VLR VLR
HLR
MSC Mobile Switching Centre
BSC Base Station Controller
VLR Visitor Location Register
HLR Home Location Register
13
Figure 8: Accessing the Internet
31. Figure 8 shows how the Internet is accessed. The traditional
narrowband method is shown at the bottom. The user dials up via the
Public Switched Telephone Network (PSTN) to the customer’s Internet
Service Provider (ISP) via a modem. Data transfer rates of up 56kbits
per second can be achieved in this way. A faster means of accessing
the Internet, using a broadband connection, is shown at the top. Using
either a Digital Subscriber Line (DSL) broadband modem or a Cable
Modem, the customer is connected to the ISP via a DSL Access
Multiplexor (DSLAM) at the exchange. Data transfer rates of 8Mbits per
second are possible over a standard line operating alongside normal
telephone use of the same line.
32. The Internet itself is a set of ISP networks and noncommercial IP
networks which connect to one another, sometimes directly, but more
often via socalled Neutral Access Points (NAP), the main UK NAP
being the London Internet Exchange (LINX). Some smaller ISPs, which
lack the connectivity of others, buy access from larger ISPs, but the
bigger ISPs continue to interconnect by free mutual ‘peering’. Some
ISPs have no network of their own and resell the services of others.
Such ‘virtual ISPs’ include names like Virgin and Arsenal Football Club.
PST
N
Interne
t
Modem
ISP
Modem
Dat
a
N/W
DSLAM
Data
N/W
DSL modem
14
Chapter 2
Types Of Telecommunications Companies In The UK
1. Since opening up the telecommunications markets to competition in the
1980s, a wide range of companies have entered the market and many
have chosen to specialise in the kinds of network they have built and
services they offer.
2. The largest telephone network remains that run by BT which reaches
everywhere in the country (save for Hull, where Kingston
Communications operates). BT and Kingston have the Universal
Service Obligation, requiring them, in their respective areas, to provide
telephone service on request to anyone who wants it.
3. Many of the other networks use the BT network to connect with each
other, so they are still involved in the vast majority of calls made in the
UK, even if they start on a cable or mobile network.
4. Since their emergence in the 1980s/90s, there has been considerable
consolidation amongst the cable companies. Since 1991, the cable
companies have exploited their right to offer telephone service as well
as cable TV over their networks. There is one other cable company that
provides telephone service. Tweedwind provides service in the Isle of
Wight and parts of Cumbria, under the trading names of Isle of Wight
Cable and Omne.
5. There are 5 mobile networks in the UK, run by Vodafone, O
2
, Orange,
TMobile and the new 3
rd
generation network operator known as ‘3’.
There is also a specialist network operated by O
2
, known as Airwave,
which is used by the police, the fire service and in the future by the
ambulance service (and in principle other essential public services) for
their own internal radio communications.
6. There are a number of businessfocussed telecommunications
companies that have, to varying extents, built their own fibre networks.
These include Cable & Wireless, Energis, VERIZON BUSINESS, Thus,
COLT, Affiniti, Your Communications, Fibrenet and many other smaller
enterprises.
7. Recognising that it’s easier to build a core network, but harder to
replicate an access network, a range of companies have entered the
market providing socalled Indirect Access services. In its simplest
form, a BT customer dials an access code of the form 1xxx followed by
the wanted number. BT routes the call to the core network identified by
the access number and the other company completes the call,
including billing for it. A development of this service which has become
very popular in the last few years, is Carrier PreSelection (CPS). With
CPS, a BT customer opts to have all (or some) of his calls routed via a
stated indirect access company, so that no access code has to be
remembered or dialled. In case of problems, a CPS customer can use
the access code 1280 to have BT route the call. With both Indirect
Access and CPS, the customer still has to be a BT customer and pay
15
the BT line rental. Companies like Centrica (under both their British
Gas and OneTel brands) are active in this market.
8. A further development of telephony competition is also now emerging,
using ‘Wholesale Line Rental’. This is often structured like CPS, but in
this case, the competing company takes over the BT line and rents it
on behalf of the customer, so that the customer only has a single
relationship with the company.
9. The Internet service provision market has been competitive since it
emerged in the early 1990s – the pioneers being Pipex and Demon
(now owned by Thus). There are still hundreds of small ISPs in the UK,
including many ‘virtual ISPs’, but there has been considerable
consolidation and concentration in the market serving domestic
customers. The main players are now AOL (whose network serving the
UK is almost entirely in the USA), Wanadoo (mainly a virtual ISP
running on the Energis network and now owned by France Telecom),
BT, NTL and Telewest.
10. Broadband Internet is currently growing rapidly. Aside from NTL and
Telewest’s cable modem service on their own cable networks, most
customers’ broadband access is via their BT telephone line, using
Digital Subscriber Line technology. BT carries the broadband
connection over its own data network before handing over to the ISP
serving the customer.
11. A few ISPs have invested in ‘Local Loop Unbundling’ (LLU), whereby
they take over the BT line and use their own DSL equipment and data
network to provide service. The most successful operator to exploit
LLU is Easynet, although they only serve business customers.
12. A few companies offer Internet access via ‘Fixed Wireless Access’,
notably Pipex and UK Broadband. ‘Wifi’ radio technology has also been
used in a few rural locations to provide Internet access on a community
selfhelp basis, though this technology has primarily been used for in
building networking (increasingly within the home) and for ‘hotspot’
services in airports, hotels and coffee shops.
13. As mentioned before, IP is becoming the dominant technology.
Whereas in the past we dialled up over the telephone network to reach
the Internet, some Internet companies are now realising that
broadband Internet access can be used to provide voice services,
though in many cases in a form quite unlike the traditional PSTN.
Companies already wellknown in this market include Skype and
Vonage, but many more are now entering the market.
14. However, even mainstream telephone companies are expected to
convert their public telephony networks to IP technology in the next
decade. They won’t use the Internet as such to route calls, but their
own, more robust, managed IP networks. Such networks are often
described as Next Generation Networks (NGNs) and their development
will have implications for the resilience of the UK network.
16
Chapter 3
Threats To Continuity Of Service
1. We have become accustomed to the fixed telephone network always
being ‘up and running’, even when our local electricity supply is lost.
Indeed, this expectation creates frustration with the more recent mobile
and Internet networks which have been built on a more commercially
oriented basis.
2. All the major telephone companies have invested heavily in ensuring
the reliability of their networks and the continuity of services running
over them.
3. In this chapter, we will consider the many threats to continuity of
service that companies need to take into account. In summary, they
can be grouped into 5 headings:
· Physical
· Loss of key inputs
· System/Logical failings
· Software failures
· Electronic ‘interference’
Physical Threats
4. These include:
· Natural phenomena (Extreme weather, earthquake, flood and
lightning)?
· Fire
· Explosions, in particular those caused by gas leaks?
· Damage caused by accidents, vandalism, internal sabotage and
terrorism.
Loss of key inputs
5. Telecommunications depends on the continuous availability of many
‘key inputs’, amongst which the most critical are:
· Electrical Power
· Fuel (for backup generators and vehicle fleet)
· Human access (to operational installations)
· Materials
6. Electricity, in particular, is the most critical input. Not only is the
telecoms industry wholly dependant on electrical power, but the
electrical power industry depends on telecoms to manage their
extensive network of generators and grid distribution.
17
System/Logical failings
7. To prevent being vulnerable to the failure of a single part of the system,
telecommunications companies will invest, where practical, in duplicate
or triplicate backups for their equipment (redundancy) and diverse
transmission routings. Thus the ‘logical’ architecture of the service will
be more resilient than the simple physical layout. But sometimes, due
often to human error, these logical configurations can themselves fail to
provide the expected level of resilience. The key is to avoid, wherever
possible, ‘single points of failure’.
8. However, not all parts of the network can be made resilient and in
these cases, the complementary processes of restoration and repair
have to be strengthened.
Software failures
9. All telecommunications networks are reliant on software controlled
equipment, and no software is immune from errors and operational
failings. Unlike personal computers, it is not acceptable for a
telecommunications network to crash and stop responding altogether.
10. A particularly worrying form of software failure is called a ‘systemic’ or
‘commonmode’ failure, where a software error in one network node
causes the same fault to occur in other connected nodes, leading to a
‘runaway’ failure of an entire network.
Electronic ‘interference’
11. Telecommunications networks, especially those increasingly using IP
technology, can be vulnerable to conditions entering the system via the
network itself. Increasingly, these can be malicious in intent.
12. A wide range of types of threat fall into this category, including:
· Inappropriate signals injected by users, either too high a voltage or
at the wrong frequency?
· Similar signal pickup problems caused by radio interference, e.g.
from amateur radio transmissions?
· Traffic overloads, often stimulated by advertising campaigns and TV
based promotions?
· Denial of Service attacks – malicious attempts to damage a service,
sometimes by traffic overload, sometimes by the transmission of
‘malware’ (malicious software)?
· ‘Malware’, such as viruses, worms and Trojans?
· Hacking, including attempts to subvert the proper operation of the
billing system in networks?
· The transmission of specifically crafted signalling messages,
designed to cause misoperation of the network
18
Chapter 4
Resilience Measures Taken By Telecommunications Companies
1. Despite the long list of threats to which a telecommunications network
is exposed, as described in Chapter 3, in practice, there are many
mitigation measures that can be taken to reduce the risk that these
threats can pose. Although no network can ever be totally ‘nonstop’,
the performance of the UK telecommunications networks, especially
the public telephone networks, are very high.
2. This is not the appropriate document in which to record all the possible
and desirable countermeasures that can be taken, but the following
gives a flavour of the typical ways in which the telecommunications
networks are secured. Some residual difficulties are also mentioned.
3. Physical Threats: Exchange buildings are fitted with smoke, gas and
flood detectors. Some buildings will be physically hardened and be
fitted with CCTV monitoring. Building access is controlled by door entry
systems which can record who have entered the building. Internal
cellular security, as well as perimeter security may be used. Radio
masts are designed to cope with high wind and iceloading.
4. Loss of key inputs: Equipment will be secured against loss of electricity
both by having a battery backup (which might support service for about
an hour) plus a diesel generator designed to cut in when the public
mains supply fails. Because the large majority of home telephones are
powered by the telephone line itself, service can be provided even
when the domestic electricity is cut off. (Some domestic phones, such
as cordless phones and answering machines do need local mains
power, however).
Power: Generator backup is not practical to secure most mobile
network base stations or street cabinets in cable networks. This means
that in an extended electrical power outage, the mobile phone networks
may become subject to failure. Equally, the phones themselves rely on
battery recharging from the mains supply.
Fuel: The Fuel Crisis showed telecommunications operators are
vulnerable to loss of fuel. However, priority provision of fuel, alongside
other essential services should ensure continuation of critical business
functions.
Access to equipment: Similarly, the Foot & Mouth crisis and events
following city centre bombings have shown that if telecommunications
staff are denied access to their installations, then they may be unable
to assist the repair of equipment needed by other essential services.
Again, recognising priority of access is needed.
Stock: Many telecommunications companies hold as little stock of
material as they can, according to modern ‘justintime’ provisioning
principles. However, many make arrangements with their suppliers to
hold emergency stocks on their behalf.
19
5. System/Logical failures: This is an issue that has to be designedin
from the start. For example each concentrator can have diverse
routings to its host local exchange. Each local exchange is then
typically connected to 3 tandem/trunk exchanges. Each trunk exchange
is connected to every other. The result of this is that any two local
exchanges have a multitude of possible paths over which calls can be
set up, so the resulting network is extremely resilient to the loss of
either individual trunk exchanges or the transmission systems
connecting them. But any given customer will still be vulnerable to the
loss of his concentrator or local exchange. For this reason, BT
maintains a group of strategically positioned trailermounted exchanges
which can be deployed where necessary for fast restoration. Similarly,
replacement power equipment and generators can be deployed. All
telephone exchanges also use duplicated computers and switch paths
internally.
6. The UK Internet has not been planned as a single logical entity, which
is both a strength and a weakness. The Internet can often reconfigure
itself in times of outage. On the other hand, many parts of the Internet
rely on just a few buildings where different Internet providers both site
their equipment and make connections with one another.
7. Mobile networks are highly reliant on the fixed network operators to
connect their base stations and exchanges together. Hence, the mobile
network cannot be seen as a separate and alternative network to the
regular public fixed network. A similar situation arises with the Internet,
where the many smaller Internet Service Providers are dependant on
others for their transmission. Hence the whole UK telecommunications
infrastructure has significant elements of mutual dependency.
8. Software failures: Exchange equipment is designed to detect software
which is not working properly, contain the problem and restart the
offending subsystem. If all else fails, the entire exchange will
automatically restart. So unlike personal computers, they never stop
entirely. To avoid ‘common mode’ failures, some companies will
deliberately use two types of equipment in their network from different
suppliers, to avoid any ‘domino failures’.
9. Electronic ‘interference’: It has to be realised that no network has
enough spare capacity to cope with the increased demand for calls
which occur during major incidents. Traffic overloads in telephone
networks can cause major problems which can be avoided by invoking
traffic management techniques, such as ‘call gapping’ which reduces
the load on the system to one that can be safely managed. In some
circumstances, priority access to the networks can be provided to
ensure that appropriate public authorities can continue to function.
10. The Internet poses special threats because its original design concept
was to provide a very open and transparent form of network. This
means that all sorts of threats arise from inappropriate use or access of
the Internet. Unlike the telephone network, which has physical
separation of its customer connectivity and its control circuits, IP
networks have only a logical form of separation and this is vulnerable to
‘hacking’. Increasingly, IP networks are being protected by extensive
20
‘firewalls’ and progressively new protocols are being deployed to avoid
the threats caused by the originally highly open nature of the Internet.
11. IP networks do have their own strengths, however. For example,
because of the packetised nature of transmission and the fact that
these packets may traverse different paths across the network, it is far
harder to ‘eavesdrop’ on an Internet connection. Additionally, it is very
easy to encrypt messages before they pass over the Internet.
12. Not all parts of the network can be secured and the single access line
from the customer to the exchange is not capable of being protected
from failure economically. So customers are encouraged, where they
need higher than normal levels of security, to invest in two separated
paths from their building, perhaps to two different telephone
exchanges.
13. Telecommunications operators will invest in resilience commensurate
with the risk to their commercial interests, including their reputations. In
a competitive environment, where prices are constantly falling,
companies will often switch from competing on price to competing on
quality. Good resilience therefore becomes a competitive imperative.
and many of the desirable resilience features that government will wish
to see are often delivered by the operation of the market itself. But not
always. In particular, the mobile and Internet industries have arisen
from a quite different commercial culture than the telephony providers.
The Internet is commonly described as a ‘best efforts’ network.
14. There are particular risks as telephone companies move towards the
adoption of Next Generation Network IP technologies. The diversity of
the present network may be reduced and switching will be
concentrated in fewer nodes than at present. The telephone network
could start to suffer some of the weaknesses described above relating
to the wider Internet. Added to that, the introduction of any new
software driven technology is likely to cause some instability before the
inevitable software bugs are driven out.
21
Chapter 5
Statutory Provisions Concerning Telecommunications Resilience
There are a range of statutes that touch on telecommunications and in
particular the issues of resilience, emergency planning and wider national
security. Few of these provide clear powers to require all telecommunications
providers to maintain the resilience of their networks and services.
Furthermore, legal opinions within government are, to a degree, divided.
Some measures have been put in place by the industry on the understanding
that national security legislation could in the last resort be used to require it.
Others, however, believe that such legislation can only be used for reasons
directly relating to national security, i.e. the maintenance of public order and
the democratic rule of law. While the loss of major Critical National
Infrastructure could in extremis become a matter of national security, it is less
clear that national security legislation could be used to require all features that
assist the maintenance of the commercial and social activities of the country.
The Communications Act 2003
This Act, which replaced almost all of the former Telecommunications Act
1984, is the primary legislation that set up Ofcom as the regulator for the
broader communications industry and implemented the new European
regulatory framework which came into force in July 2003. Instead of the
former licensing regime of the Telecommunications Act, the new Act regulates
communications providers by means of general authorisations which are
required to be complied with as a condition of operating in the market.
In particular, Section 51 defines the subject matter that can be included by
Ofcom in the general Conditions of Entitlement. Section 51(1)(c) specifies
“conditions making such provision as OFCOM consider appropriate for
securing the proper and effective functioning of public electronic
communications networks” and thereby empowers Ofcom to implement Article
23 of the Universal Service Directive, entitled Integrity of the Network. It has
done so through Condition 3 of the Conditions of Entitlement:
3. PROPER AND EFFECTIVE FUNCTIONING OF THE NETWORK
3.1 The Communications Provider shall take all reasonably practicable steps to maintain, to the greatest
extent possible:
(a) the proper and effective functioning of the Public Telephone Network provided by it at fixed
locations at all times, and
(b) in the event of catastrophic network breakdown or in cases of force majeure the availability of the
Public Telephone Network and Publicly Available Telephone Services provided by it at fixed
locations, and
(c) uninterrupted access to Emergency Organisations as part of any Publicly Available Telephone
Services offered at fixed locations.
3.2 The Communications Provider shall ensure that any restrictions imposed by it on access to and use of a
Public Telephone Network provided by it at a fixed location on the grounds of ensuring compliance with
paragraph 3.1 above are proportionate, nondiscriminatory and based on objective criteria identified in
advance.
3.3 For the purposes of this Condition, “Communications Provider” means a person who provides a Public
Telephone Network at a fixed location and/or provides Publicly Available Telephone Services at a fixed
location.
22
Condition 3 only applies to providers of fixed telephony. It does not therefore
provide for any regulation of the resilience of mobile or Internet services.
Condition 3.2 goes slightly beyond the requirements of Article 23, but
continues a similar regulation contained in the old Condition 20 of the former
licence for Public Telecommunications Operators which was in force until July
2003.
Oftel, the predecessor of Ofcom, produced guidance for the industry on what
issues it expected should be considered when assessing whether companies
were complying with Condition 20. These are known as the “Essential
Requirements Guidelines” (published in October 2002) and while Ofcom no
longer wishes to act as author of such guidance, the material is currently
being revised as part of the Tripartite arrangements between the Cabinet
Office, BERR and Ofcom.
In practice, while Condition 3 impacts all telephony providers, as with most
regulation, there is no proactive compliance checking. Compliance action has
been restricted to events following a major network failure, for example, the
Southampton outage of 2002 and the Manchester fire of 2004.
However, compliance to the ‘Essential Requirements’ Guidelines was made
part of the voluntary elements within the National Emergency Plan for the UK
Telecommunications Sector (see Chapter 7).
23
Emergency Planning
Section 51(1)(e) specifies “conditions requiring or regulating the provision,
availability and use, in the event of a disaster, of electronic communications
networks, electronic communications services and associated facilities” and
thereby empowers Ofcom to implement conditions requiring providers to
assist central and local government in times of emergencies. This is
specifically allowed (though not mandated) by paragraph 12 of Annex A to the
Authorisation Directive and continues previous obligations on Public
Telephone Operators in their former licences.
Oftel published under 5.1(b) a list of emergency planning bodies in county and
unitary authorities, plus those central government departments with
emergency planning responsibilities.
Providers are not expected to seek out such departments, but will be
expected to respond appropriately when approached, either in advance, to
plan for some future contingency, or at the time of an event, such as a local
flood, storm etc.
The existence of this condition has assisted the voluntary production of the
National Emergency Plan for the UK Telecommunications Sector (see
Chapter 7).
Given that the previous licence condition only affected Public Telephone
Operators, it was deemed appropriate to limit the class of provider to whom
5. EMERGENCY PLANNING
5.1 Subject to paragraph 5.3, the Communications Provider shall, on the request of and in consultation
with:
(a) the authorities responsible for Emergency Organisations? and
(b) such departments of central and local government as Ofcom may from time to time direct for
the purposes of this Condition,
make arrangements for the provision or rapid restoration of such communications services as are
practicable and may reasonably be required in Disasters.
5.2 Subject to paragraph 5.3, the Communications Provider shall, on request by any person as is
designated for the purpose in any such arrangements, implement those arrangements in so far as is
reasonable and practicable to do so.
5.3 Nothing in this Condition precludes the Communications Provider from:
(a) recovering the costs incurred in making or implementing any such arrangements? or
(b) making the implementation of any such arrangements conditional upon being indemnified by
the person for whom the arrangements are to be implemented for all costs incurred as a
consequence of the implementation.
5.4 For the purposes of this Condition:
(a) “Communications Provider” means a person who provides a Public Telephone Network
and/or provides Publicly Available Telephone Services? and
(b) “Disaster” includes any major incident having a significant effect on the general public? and
for this purpose a major incident includes any incident of contamination involving radioactive
substances or other toxic materials.
24
this condition applies. However, by limiting it to telephone providers, it was
realised after the event that it does not apply to the two major suppliers of
transmission services to the broadcasters.
Section 132
Section 132 of the Communications Act provides powers for the Secretary of
State to direct Ofcom to suspend, in whole or in part, the authorisation of a
provider to provide networks or services, where he has reasonable grounds
for believing that it is necessary to do so to protect the public from any threat
to public safety or public health, or in the interests of national security. This is
permitted by Article 3 of the Authorisation Directive and flows from over
arching powers of Member States under Article 46(1) of the European Treaty.
Powers to restrict or limit providers’ services on the grounds of national
security have existed since the very beginning of telecommunications. Prior to
the new European regulatory framework, similar powers were included in SI
98/1580. As early as 1848, the Secretary of State used such powers to
prevent Chartists from coordinating their nationwide protest activities using the
telegraph system, which at the time was in private hands, using powers under
the Electric Telegraph Act of 1846.
Cutting off communications in times of national crisis is quite common
following coups and rebellions in other jurisdictions, but in today’s society, with
its loathing of censorship, it is difficult to see such powers ever being used in
peace time. Additionally, the powers are of their very nature restrictive and do
not provide for making orders for providers to provide positive assistance to
the government in times of emergency.
Telecommunications Act 1984
As mentioned above, the Communications Act repealed almost all of the
former Telecommunications Act of 1984, which had introduced competition,
privatized BT and set up Oftel.
However, paragraph 70 of Schedule 17 of the Communications Act 2003
amended Section 94 of the Telecommunications Act and this remains one of
the few sections of the former Act still in force. Section 94 allows the
Secretary of State to give directions to providers of public electronic
communications networks, or Ofcom, in the interests of national security, or of
relations with a foreign country. The directions are to be laid before
Parliament, unless the Secretary of State considers that disclosure is against
the interests of national security, or of relations with a foreign country, or the
commercial interests of some other person. The Secretary of State has
power to defray costs incurred in complying with any direction.
Civil Contingencies Act 2004
This recent piece of legislation updates the very antiquated Emergency
Powers Act of 1920, a statute so old that telecommunications was not
included at the time. This explains why the Emergency Planning obligations
have always been separately placed on providers, such as Condition 5
described above. Its definition of ‘emergency’ includes ‘disruption of a system
25
of communication’, though much of the thrust of the Act is to modernise the
ways in which bodies respond to emergencies at the local level.
Section 22 of Schedule 1 of the Act defines all network providers who supply
telephone services to be “Category 2 responders”. Such responders are
required to provide information to other emergency bodies and collaborate
with them on making contingency plans for all kinds of emergency. There has
been some concern that given the number of local committees to be set up to
do this at a local level, that it would represent an undue burden on a large
number of providers. In practice, providers are likely to represent one another
so that the burden is shared and minimised. There have been other concerns
that the duty to collaborate partly overlaps the obligations under Condition 5.
Condition 5 does go further however, in that it requires that network providers
not only plan but implement planned services on request.
If an Emergency is declared under Part 2 of the Act, then ministers would
have wide powers to direct bodies to do things, including anything required
under Section 22(2)(e) for the purpose of protecting or restoring a system of
communication. Under this Act, an Emergency is not the same as a Disaster
as used in Condition 5.
See definition and list of Category Two Responders in ANNEX 2.
Other Statutes
Although outside the primary scope of this document, it should be noted that
there are other Acts which impinge on communications providers and that the
above does not therefore represent the totality of the statutory or regulatory
burden on providers. In particular, in relation to national security and law
enforcement for serious crime, there are two Acts that relate to obligations on
lawful interception and the retention of communications data. Policy on these
matters rests with the Home Office.
The Regulation of Investigatory Powers Act 2000 (RIPA)
Lawful interception can only be carried out through warrants issued by a
Secretary of State to one of the 9 intercepting agencies listed at Section 6(2)
of the Act. Communications Providers are required to provide assistance to
these bodies when requested, subject to the request being reasonably
practicable (Section 11).
The AntiTerrorism, Crime and Security Act 2001
Implemented in the wake of ‘9/11’, this statute, in Part 11, requires
Communications Providers to retain communications data. However, it has
not been formally implemented and data retention continues to be promoted
and governed by a voluntary code of practice. Steps are currently being taken
to seek a harmonized European approach to data retention requirements.
Limitations
It is important to recognise that some threats to the telecommunications
network are global or external in character, so national legislation alone
26
cannot solve everything. However, there is extensive cooperation amongst UK
agencies with those in other countries with sympathetic objectives in respect
of national security.
27
Chapter 6
Roles of Government Departments, the Regulator and other
Agencies
Department for Business, Enterprise and Regulatory Reform (BERR)
The DTI has the primary policy responsibility for the telecommunications
industry, including regulatory matters. The Cabinet Office, while being the
main department for coordinating government policy on emergency planning,
relies on a system of lead government departments to oversee the delivery of
resilience within their areas of competence. In particular, DTI takes that lead
role for telecommunications and ensures that appropriate resilience
arrangements are in place. In practice, this is delivered through a Tripartite
arrangement between DTI, the Cabinet Office and Ofcom, with support from
specialist agencies such as NISCC and NSAC (see below).
Cabinet Office, Civil Contingencies Secretariat (CCS)
The CCS was set up in July 2001 to improve the UK's resilience against
disruptive challenges through working with others to anticipate, assess,
prevent, prepare, respond and recover. It defines resilience as the ability at
every level national, regional and local to detect, prevent and if necessary
handle disruptive challenges. These could range from floods, through
outbreaks of human or animal disease, to terrorist attacks.
Its objectives are to:
· lead horizon scanning activity to identify and assess potential and
imminent disruptive challenges?
· lead the delivery of improved resilience across Government and the
public sector?
· ensure that the Government can continue to function and deliver public
services during crisis? and
· improve the capability of Government and other stakeholders to
prepare for, respond to and manage potential challenges.
Cabinet Office, Central Sponsor for Information Assurance (CSIA)
The CSIA works with partners in the public and private sectors, as well as its
international counterparts, to help safeguard the nation's IT and
telecommunications services.
Its broad focus is on safeguarding IT systems but also has a specific remit
within the telecommunications area to identify and address vulnerabilities of
national telecommunications systems and progress their resolution in
conjunction with other government departments and organisations. CSIA also
coordinates a range of services and facilities for use in emergencies, such the
28
Government’s Emergency Communications Network, the Government
Telephone Preference Service and its mobile counterpart ACCOLC (Access
and Overload Control).
National Infrastructure Security Coordination Centre (NISCC)
Within the Government’s broad role to promote the protection of the Critical
National Infrastructure, NISCC’s role is to minimise the risk to the CNI from
electronic attack.
NISCC has no regulatory, legislative or law enforcement role? it seeks to
achieve its aim through four broad work streams:
· Threat Assessment. Using a wide range of resources to investigate,
assess and disrupt threats.
· Outreach. Promoting protection and assurance by encouraging
information sharing, offering advice and fostering best practice.
· Response. Warning of new threats? advising on mitigation? managing
disclosure of vulnerabilities? helping the CNI investigate and recover
from attack.
· Research and Development. Devising the most advanced techniques
and methods to support efforts across all work streams.
NISCC was set up in 1999 and is an interdepartmental centre drawing on
contributions from across government. Defence, Central Government Policy,
Trade, the Intelligence Agencies and Law Enforcement all contribute expertise
and effort.
National Security Advice Centre (NSAC)
NSAC is part of the Security Service and contributes to the protection of key
Government assets and the UK's Critical National Infrastructure (CNI),
including telecommunications, and to the reduction of their vulnerability to
terrorism and other threats. NSAC works with telecommunications providers
identifying those parts of their systems which represent a significant risk to the
CNI and can provide advice on physical and personnel protective security.
Office of Communications (Ofcom)
Ofcom is the regulator for the communications industry and assumed the
powers of the former regulators (such as Oftel) in December 2003. Unlike
Oftel, it is not a Government department, but a Public Corporation.
Ofcom’s role includes ensuring compliance by providers to their Conditions of
Entitlement, including Conditions 3 and 5 as described in Chapter 5. Ofcom
investigates major failures within the telecommunications system and provides
advice to DTI and the Cabinet Office as part of the Tripartite arrangements.
29
Chapter 7
Emergency Plans And Response Measures
However well telecommunications providers build their networks and systems,
the investment in resilience will always reflect the perceived risks, the known
vulnerabilities and the practicality of trying to protect assets against the
increasingly uncertain modes of attack by malicious parties. It is therefore
important that as well as building in resilience and other mitigating measures
against risks, there should be clear plans and response measures should
emergency situations arise.
Telecommunications providers have always worked with Emergency Planning
organisations in both central and local government to deliver support for
emergencies in the community.
Under CSIA’s chairmanship, the Telecommunications Industry Emergency
Planning Forum operates to two key documents:
· The National Emergency Plan for the UK Telecommunications Industry?
and
· The Memorandum of Understanding for cooperation in emergency
situations
There is also a nondisclosure agreement which protects any shared
information from being passed outside the emergency planning community.
The Emergency Plan contains information on emergency contact points
(which are regularly exercised), emergency scenarios (both those identified
within the industry and those communicated from Government), management
processes for handling emergencies and priority customers & services.
The Memorandum of Understanding allows the sharing of human and material
resources amongst providers when required in an emergency.
The Emergency Planning Forum continues to oversee the maintenance of
these documents and is working on further activities to identify risks and
improve resilience.
30
Annex 1 – Typical core network of a smaller operator
This kind of network could be provided either by selfbuild or by acquiring
dark fibre leases. In contrast, BT’s core network reaches every city, town
and many villages in the entire country and their access network serves
almost every building.
Exeter
Bristol
Reading
Portsmouth
Dover
Lowestoft
Milton Keynes
Leicester
Sheffield
Newcastle
Manchester
Birmingham
Edinburgh
Berwick
Middlesborough
Preston
Carlisle
Newbury
Swindon
Basingstoke
Brighton
Glasgow
Leeds
31
ANNEX 2
Civil Contingencies Act 2004, Definition of Category Two Responder
22 (1) A person who provides a public electronic communications
network which makes telephone services available (whether for
spoken communication or for the transmission of data).
(2) In subparagraph (1)
(a) the reference to provision of a network shall be construed
in accordance with section 32(4)(a) and (b) of the
Communications Act 2003 (c. 21), and
(b) "public electronic communications network" shall have the
meaning given by sections 32(1) and 151(1) of that Act.
List of Telecoms Category 2 Responders
1
Company Type of Service
Affiniti
2
Fixed
BT Fixed
Cable & Wireless Fixed
COLT Fixed
Global Crossing Fixed
3 Mobile
Kingston Communications Fixed
Level 3 Fixed
NTL
3
Fixed
O
2
Mobile
Orange Mobile
T Mobile Mobile
Telewest Fixed
Thus Fixed
Vodafone Mobile
Verizon Business Fixed
1
Comprising major companies that (as defined under the CCA) provide a public
electronic communications network which makes telephone services
available (whether for spoken communication or for the transmission of data).
2
Affiniti is part of the Kingston Communications Group.
3
NTL and TeleWest are in merger discussions.
32
Glossary
ACCOLC Access and Overload Control, a system designed to give
priority access to mobile networks in times of stress.
AOL America On Line – a major USbased Internet Service
Provider
ATM Asynchronous Transfer Mode, a system for high speed data
transmission.
Base Station The part of a mobile telephone network where the radio
antenna is sited.
CCS Civil Contingencies Secretariat, part of the Cabinet Office
which coordinates civil emergency matters.
CCTV Closed Circuit Television
CNI Critical National Infrastructure, the key assets, services and
systems that support the economic, political and social life of
the UK.
CPS Carrier PreSelection, a service whereby telephone
customers can have their calls routed via another network
without having to dial a specific code.
CSIA Central Sponsor for Information Assurance, part of the
Cabinet Office, which has a coordinating role in telecoms
resilience matters.
DSL Digital Subscriber Line, a technology which allows a normal
telephone line to carry broadband data.
DP Distribution Point, the final part of the local access network
where connections are made to individual homes, often
mounted on a telegraph pole.
FDDI Fibre Distributed Data Interface, a system for high speed
data transmission over fibre, typically across campus sites.
Frame Relay A medium speed system for data transmission, often used
within corporate networks.
Gbit/s Gigabits per second, that is, a data transmission rate of 10
9
bits per second.
GTPS Government Telephone Preference System, a facility
whereby priority can be given to public authorities on the
fixed telephone network.
33
Head End The central building in a cable network where the TV signals
are distributed.
Internet A global system of Interconnected Networks, using a
common technical basis.
Intranet An internal, corporate network using the same IP protocols
as the Internet.
IP Internet Protocol, the base protocol used for data
transmission on the Internet.
ISP Internet Service Provider
LINX The London Internet Exchange, were ISPs connect their
networks together to exchange traffic.
LLU Local Loop Unbundling, a facility whereby a telecoms
provider can use the copper loops of the BT network to
provide their own competing broadband data services.
MDF Main Distribution Frame, an arrangement of connections
assembled on a large gantry which allows the external
copper circuits to be crossconnected to any piece of
internal equipment in an exchange building.
NAP Neutral Access Point, such as the LINX, where ISPs
connect their systems together.
NGN Next Generation Network, a multiservice network mainly
based on IP technology which is set to replace the present
telephone network.
NISCC National Infrastructure Security Coordination Centre, a
crossdepartmental agency which focuses on electronic
security of the CNI.
NSAC National Security Advice Centre, part of the Security Service
that specialises in physical security.
Ofcom Office of Communications, the UK communications
regulator.
Oftel Office of Telecommunications, the former telecoms regulator
19842003.
PCP Primary CrossConnect Point, typically a green roadside
cabinet where local copper cables are crossconnected.
Private Circuits Sometimes called Leased Lines, these are pointtopoint un
switched telecoms circuits, used by businesses and other
providers to link sites together on a permanent basis.
PSTN Public Switched Telephone Network, the ordinary phone
34
network.
SMDS Switched MultiMegabit Data Service, a system of high
speed data transmission, a precursor to ATM.
WiFi Wireless Fidelity, a radio system used for connecting
computers together over short distances, in homes, offices
or at public ‘hotspots’.
WLR Wholesale Line Rental, a service whereby a competitor to
BT provides telephone service by reselling the BT network,
in a similar way that ‘airtime providers’ provide service over
mobile networks.
X25 A system of medium speed data transmission which has
now largely been replaced by IP.
doc_715574774.pdf
The telecommunications industry contributes around 45% of the country's Gross Domestic Product (GDP) and might therefore be considered of relatively minor importance to the country. However, its own GDP does not reflect the wider importance that telecommunications plays in the economic and social wellbeing of the country.
1
Telecommunications Networks – a vital
part of the Critical National Infrastructure
Version 1.1
2
Telecommunications Networks – A Vital Part of the Critical
National Infrastructure
CONTENTS
page no
Executive Summary 3
Introduction 4
Chapter 1: The Nature of UK Telecommunications Networks Describes the
nature of the UK telecommunications networks. If you are familiar with telecommunications,
you may want to skip straight to Chapter 2. 5
Chapter 2: Types of Telecommunications Companies in the UK Describes
the commercial environment and the wide variety of telecommunications providers in the
market, which collectively make up the ‘UK Network’. 14
Chapter 3: Threats to Continuity of Service Describes the wide range of threats
to the continuity of service over the UK networks. 16
Chapter 4: Resilience measures taken by telecommunications
companies Covers the typical measures taken by the network companies to meet the
challenges posed by these threats and mentions some of the remaining residual problems.
18
Chapter 5: Statutory provisions concerning telecommunications
resilience Telecommunications is now a competitive private sector activity, there are a
range of statutory provisions that touch on the government’s ability to assure the resilience of
the UK networks and these are described in Chapter 5.
21
Chapter 6: Roles of Government departments, the regulator and other
agencies Sets out the roles and responsibilities of the various government
departments, the regulator (Ofcom) and other agencies, describing how in practice they work
together as an extended team in assuring resilience. 27
Chapter 7: Emergency Plans and response measures Covers the present
arrangements in the telecommunications sector which ensure that industry and government
work effectively together in emergencies and other times of stress. 29
Annex 1: Typical Smaller Network 30
Annex 2: Definition and List of Category Two Responders 31
Glossary 32
3
Executive Summary
This document explains how the UK’s telecommunications networks are a
vital component of the country’s Critical National Infrastructure, the ways in
which resilience in both networks and services is achieved and the roles of
government and other agencies in the maintenance of this capability.
This document contains information for all those who need to have a basic
understanding of the electronic communications environment, ranging from
Senior Information Risk Owners (SIRO’s), Business Continuity Managers and
Emergency Planners in central, regional and local government as well as
businesses part of the CNI.
Recently, telecommunications has been going through radical change. Many
of these changes are being influenced by the convergence of technologies,
particularly computers and telecommunications, as well as broadcast, the
internet and other information services. This convergence of technologies, has
led to the era of the Information Society. It has always been acknowledged
that telecommunications is essential for the economic, social and cultural
development of society, but that requirement has become even more evident
as the Information Age is increasingly recognised as the future of all societies.
From a regulatory perspective, the European Directives are encouraging a
free market approach and the UK regulator Ofcom recognises that this
approach will bring new services, technologies and opportunities for increased
innovation and potential for competition leading to reduced costs.
There are regulatory obligations on electronic communications providers in
relation to resilience and emergency planning? for the wider market there are
duties and powers provided through a number of different pieces of
legislation. However, the industry has shown its ability to work with
government on a voluntary basis to improve emergency planning
arrangements. These plans are well developed and regularly tested.
Most central and local government telecommunications systems are today
provided by the industry, and there is a requirement for customers of these
services to have some form of understanding of how the UK Telecom Network
functions. This document aims to fulfil this need.
4
Introduction
The telecommunications industry contributes around 45% of the country’s
Gross Domestic Product (GDP) and might therefore be considered of
relatively minor importance to the country.
However, its own GDP does not reflect the wider importance that
telecommunications plays in the economic and social wellbeing of the
country. Almost every UK business is dependent on telecommunications to
transact business, as is every branch of central and local government and
related public bodies.
The social life of the country is highly dependent on telecommunications too,
be it the capability to broadcast TV to every home, for friends to ‘text’ one
another to arrange their appointments or for anyone to summon the
emergency services via 999. The defence and security of the nation is also
highly dependent on reliable communications. Telecommunications therefore
has a ‘multiplier’ effect and its importance to the overall continuity of life and
the democratic tradition of this country is immense. Such is its importance that
governments have recognised that the issue often transcends the narrower
commercial interests of the companies who supply services and therefore
government has some duty to assure the resilience of the country’s
telecommunications systems and services.
For many years prior to 1984, telecommunications was run by the government
as a statutory monopoly. It could ensure that the General Post Office (GPO)
took due account of the requirement to serve the country in an appropriate
way, with adequate provision for the resilience of the system. Since 1984, not
only has telecommunications been provided in an increasingly competitive
commercial environment, but also a much wider range of services has
become available – and come to be relied on – such as mobile phones and
the Internet. Government now has to proceed partly based on supporting
statutes, but to a large extent by voluntary cooperation by the industry.
Critical National Infrastructure
The importance of telecommunications resilience is reflected in the fact that
government has identified telecommunications as one of the top 10 sectors
deemed to be part of the ‘Critical National Infrastructure’ (CNI). The
government views the CNI as those assets, services and systems that support
the economic, political and social life of the UK whose importance is such that
any entire or partial loss or compromise could:
· cause large scale loss of life
· have a serious impact on the national economy
· have other grave social consequences for the community
· be of immediate concern to the national government
Telecommunications fits with each of these 4 points.
5
Chapter 1
The nature of the UK’s telecommunications networks
1. Before explaining the threats to the UK telecommunications capability
and the means of mitigating those risks, it is important to understand
the nature of telecommunications networks and the kinds of company
that now provide those networks and/or the services running over
them. Those familiar with telecommunications networks may wish to
skip to Chapter 2.
2. The fundamental principle of telecommunications is the ability to
transmit information over a distance. Transmission systems comprise
three elements:
· A Transmitter?
· A Transmission Medium? and
· A Receiver
3. The Transmitter converts the information into a form of energy
appropriate to the Transmission Medium in use and injects that energy
into the Transmission Medium. The Transmission Medium conveys the
energy over a path to the Receiver. The Receiver converts the
received energy into a form suitable for use at the receiving location,
thereby creating a distant replica of the original information. Although
TV signals are broadcast oneway out towards viewers, most
transmission systems are bidirectional, allowing conversation and
interaction between 2, or sometimes more, parties.
4. All forms of telecommunications use different types of electromagnetic
energy and the principle types of transmission media are:
· Electrical signals over metallic wires?
· Radio waves through the air and space?
· Light signals through optical fibres
5. All of these are different forms of electromagnetic energy, but differ
widely in the frequencies of the signals used. The list is not exhaustive,
for example, low frequency short range magnetic coupling is used for
systems like hearing aid loops for the hard of hearing and infrared light
is used to communicate between our TVs and their remote controls.
Though these technologies aren’t used for public networks, they are all
forms of telecommunication.
6. In order to understand the role that individual transmission systems
play within the telecommunications network, it is useful to describe the
overall structure and use of the network.
7. A telecommunications network comprises two main parts:
6
· The core network, comprising a large number of buildings (mostly
telephone exchanges) connected together by transmission systems?
· The local or access network comprising copper and some fibre
cables connecting individual customer premises into the core
network at the local telephone exchange building.
Although BT’s network is the largest and serves the entire country’
each telecommunications network company has its own core network
and its own access network,. However, it is impractical for other
competing operators to completely replicate the scale of BT’s network,
so they may rely on acquiring capacity or facilities from BT or other
operators in order to construct their desired network. So a competing
operator may construct its own small fibre network connecting the
major cities and rely on other means to connect to areas and
customers ‘offnetwork’. Many operators start by constructing a ‘figure
of 8’ network connecting, typically, London, Bristol, Birmingham,
Manchester and Leeds? paralleling the early deployment of both canals
in the 18
th
century and railways in the 19
th
century.
Figure 1: A small core network
The core network
8. In the core network, the most usual transmission medium is optical
fibre, which comprises a length of very pure glass, about the thickness
of a human hair, capable of carrying light signals over a considerable
distance (100s of kms). Other transmission media are sometimes used,
such as microwave radio or satellites. In the case of optical fibre, the
transmitter consists of a laser which generates a strong pure light
source, while the receiver consists of a light detector which indicates
the presence or absence of light signals. The fibre optic system works
by rapidly switching the light source on and off, many millions of times
a second, thereby producing a system capable of conveying a digital
information stream, that is, a stream of signals representing the binary
states 1 and 0 (on/off). Information, be it voice, video or data is coded
into a digital form prior to transmission. Individual fibre strands are
protected by a plastic sheath and then bundled together in groups of
between typically 24 and 96 to form a fibre cable, with its own outer
A core network of
exchanges
connected by a
mesh of fibre optic
cables
7
sheath and strengthening core. Each strand is isolated from the others
and capable of separate use.
9. Sometimes the network of cables is organised into sets of discrete
hierarchical rings and sometimes in a less structured mesh. At the ends
of the fibre systems, including those at points round the ring structures,
the light signals are converted back into electrical signals and
connected to a multiplexer. The function of the multiplexer is to allow
many separate individual circuits (which may be carrying individual
telephone calls or private circuits) to share the capacity provided by the
individual fibre. This is possible because the fibre cable may provide
for, say, 10 Gigabits per second (Gbit/s) to be conveyed, whereas a
single telephone call only occupies 64kbit/s. Such a system could
therefore convey over 150,000 separate simultaneous calls. This
capacity sharing is achieved by the technique of Time Division
Multiplexing, whereby each call or circuit is allowed in turn to transmit 8
bits on the fibre every 125 microseconds.
10. The BT core network comprises around 5500 telephone exchanges
connected together by fibre optic systems. This extensive network then
connects to around 350 buildings where regional and trunk networks
are focussed.
11. Other core networks are much smaller and may only use about 540
exchanges and a few hundred ‘points of presence’ where connection
from customers is made via their own access circuits or by renting
circuits from other operators. A diagram of a typical smaller network is
shown at Annex 1. Such smaller networks often reflect the company’s
focus on business customers in major cities.
The local or access network
12. The purpose of the local or access network is to connect individual
customers to the nearest suitable point on the corer network, often the
local telephone exchange. There are three broad types of access
network:
a. BT’s network, covering virtually every home and office in the
country and largely made up of copper cables, but with fibre
links for serving larger businesses?
b. Competitor networks focussing on business customers, almost
exclusively comprising fibre cables, with some use of microwave
radio?
c. The Cable TV company networks, which also provide telephony
and other telecom services, which comprise a hybrid network of
fibre cables with final delivery via copper coaxial or pair cables.
13. The BT access network mainly comprises copper cables stretching
from the telephone exchange out to individual homes and offices. It is
structured in a ‘tree and branch’ manner, with very large cables, of up
to 4800 copper pairs, extending from the exchange Main Distribution
Frame (MDF) through underground ducts, to roadside cabinets, known
8
as Primary Crossconnect Points (PCPs). At the PCP, individual copper
pairs are crossconnected to others in smaller cables that then radiate
out to many individual Distribution Points (DPs). A DP will typically be
sited at the top of a telephone pole or within larger office buildings.
From the DP, individual copper pairs are delivered to each home, in the
case of a telephone pole sited DP, this will be via a dropwire, strung
between the pole and the home. The pair of copper wires is often
called the copper loop. The figures below show how a customer’s
home is connected to the network and the overall topology of the
access network.
Figure 2: Typical layout of a local access network
14. The outcome of this structure is to provide for every customer a pair of
copper wires that act as a single pair of electrical conductors from their
abode to the telephone exchange building, where they are terminated
on the Main Distribution Frame (MDF). From there, the pairs are
connected either to the telephone exchange equipment or to other
telecommunications apparatus provided for other types of service, such
as data services or private circuits.
15. In the case of large office buildings which have large demands for
telecommunication services, fibre cables may be provided instead of
copper, as the revenue may justify the higher capital expenditure.
16. An important distinction between the core network and the access
network is that the former comprises mainly high capacity transmission
systems shared across many types of use, while the latter is mainly low
capacity wires, each dedicated to a single customer.
17. The other business focussed companies (e.g. Cable & Wireless,
Energis, VERIZON BUSINESS, Thus, COLT, Affiniti, Your
Underground cables are carried in
earthenware ducts (4, 6, or 12 tube)
laid in trenches. However, recent
construction will often use single
plastic tubes, as nonBT providers
use.
MDF
Exchange
Cable
Chamber
Distribution Pole
Street
Cabinet or
Primary
Cross
Connect
Point (PCP)
48 pair
6004800 pair
9
Communications) may have extensive ownbuild access fibre networks
in London and other major cities, but typically will otherwise provide
their own fibre access links to customers only where the demand
justifies the bespoke construction. Unlike the copper pairs used to
deliver a single telephone line, these fibre cables, like those used in
core networks, can handle many separate circuits and services and
generate much higher revenues, often for corporate data services
rather than plain telephony.
18. In March 2006 ntl and Telewest completed a merger creating the UK's
largest residential broadband communications company delivering both
television, broadband and telephony to about 50% of UK homes
(though takeup is less than this, around 12%). Their access networks
use a combination of fibre to the street cabinet then a mixture of coaxial
cable to carry TV and copper pairs for telephony from the cabinet to the
home.
How a telephone call is connected
19. The following brief description is given of how a telephone call is
established..
20. The call is initiated by the caller lifting the handset which causes
current to flow round the copper pair loop and this is detected at the
telephone exchange. The wanted number is dialled and the exchange
analyses the dialled digits to determine which direction the call is to be
routed. The call will be extended by the exchange providing a cross
connection, for the duration of the call, from the local copper loop to a
digital channel amongst many on a multiplexed fibre cable connected
to the next exchange. Successive exchanges repeat the routing until
the call reaches the local exchange of the wanted customer, where it
will be connected to that customer’s local copper loop and the bell
rung. Different calls will take different paths through the network, but
the routing through the local access network is always fixed, as each
customer has a dedicated copper loop from his premises to a local
exchange.
Final
Distribution
Point
Video
Amplifiers
Coax
Street
Mux in
cabinet
Fibre
TV
Cable TV HeadEnd & Exchange
Siamese cable
(coax plus 2
copper pairs)
Copper pairs
TV LE
10
Figure 5: Telephone network architecture
21. In practice, the network is a little more complicated than this simple
description. The local exchange to which customers are connected
actually comprises two parts, a remote concentrator with limited
functionality to which the copper loops are connected in over 5000
towns and villages and a more complex computercontrolled ‘host’
exchange located in the nearest principal town. The ~740 local
exchanges are connected via a network of over 100 trunk or tandem
exchanges located in around 80 major locations across the country.
22. Some operator’s networks have far fewer telephone exchanges and in
general do not use remote concentrators. The smallest companies
have only a single switch ‘layer’. Customers are connected via fibre or
hybrid fibre/copper networks. However, the principle of stage by stage
call establishment is the same.
Private Circuits
23. As well as providing a telephone network, the transmission network can
be used to provide business customers with Private Circuits. A Private
Circuit, unlike a telephone call, is not designed to connect from one
point to any other? rather it provides a permanent connection between
two specific end points, such as two branch offices. A private circuit is
formed by connecting, on a semipermanent basis, the local access
circuit at one end to a path through the core network of multiplexed
fibre cables until it reaches the distant exchange building, where it will
be connected to the local access circuit of the farend point. Unlike a
telephone call which disconnects when the caller finishes the call, this
connection remains held all the time, as long as the customer
continues to rent the Private Circuit service. However, like a telephone
call connection, while the routing through the access network is fixed,
the routing through the core network can vary and may rapidly change
in response to faults in the network or other planned rearrangements.
This rerouting is performed by using electronic crossconnect
equipments situated in exchange buildings. Furthermore, the Private
Approx 100+ tandem
exchanges in about 80
major locations
About 5000
concentrators in
almost every town
and village
About 740 local
exchange ‘host’
units in about 300
buildings
11
Circuit will be occupying capacity on the core network of multiplexed
cables and sharing these cables with many thousands of other Private
Circuits or channels used in the telephone network.
Figure 6: Typical arrangement and routing of a Private Circuit
Supporting others’ infrastructure needs
24. Because Private Circuits provide transparent capacity between end
points, a telephone company may rent a Private Circuit service from
another telephone company in order to provide the underlying
transmission it needs to build its own network. For example, a mobile
telephone company will rent Private Circuits in order to connect its
radio base stations to its network of exchanges.
25. Alternatively, a company may acquire the right to use individual fibre
strands in another company’s cable. This is known as a ‘dark fibre’
lease.
26. Hence, many telecommunications networks are dependent on others
and resilience may depend on the performance of several operators.
Mobile Networks
27. Mobile phone networks represent a special type of network which
shares many attributes of fixed networks but several critical differences.
28. Like a fixed network, the core network comprises a network of
telephone exchanges connected by fibreoptic cables. However the
access network is quite different, comprising a set of Base Station
Controllers and the many Base Stations themselves (the antenna sites)
which then communicate with handsets using radio. Additionally, the
core network has several databases, known as Location Registers
which keep track of the location of handsets as they move around.
Dedicated
link to
customer
through
the access
network
Dedicated
link to
customer
through
the access
network
Route (in red) over which the private
circuit is being carried at a given
time, sharing capacity with many
other circuits
Black (dashed) links show
other paths that the circuit
might occupy when other
links fail or require
maintenance
Electronic multiplexers
which crossconnect
individual circuits from
one link to another
Core Network
12
Figure 7: Typical mobile network
Internet
29. The Internet represents the other dominant form of network in use
today. Since the 1970s there have been many types of data network
deployed using a wide range of technologies and acronyms (e.g. X25,
Frame Relay, ATM, SMDS, FDDI… ). However, the development of the
Internet, especially since its commercial exploitation from the early
1990s, has been dramatic and now IP (Internet Protocol) is not only the
data network protocol of choice, but is likely to become the technology
over which almost all forms of future network are built, including the
traditional public telephone network.
30. It is important therefore to distinguish between the public Internet,
which is a ‘network of networks’, all interconnecting with the same set
of protocols and the use of IP technology to build entirely private
networks (‘intranets’) and other managed IP networks which might be
used for the provision of more robust public telephone services.
MSC MSC
BSC
VLR VLR
HLR
MSC Mobile Switching Centre
BSC Base Station Controller
VLR Visitor Location Register
HLR Home Location Register
13
Figure 8: Accessing the Internet
31. Figure 8 shows how the Internet is accessed. The traditional
narrowband method is shown at the bottom. The user dials up via the
Public Switched Telephone Network (PSTN) to the customer’s Internet
Service Provider (ISP) via a modem. Data transfer rates of up 56kbits
per second can be achieved in this way. A faster means of accessing
the Internet, using a broadband connection, is shown at the top. Using
either a Digital Subscriber Line (DSL) broadband modem or a Cable
Modem, the customer is connected to the ISP via a DSL Access
Multiplexor (DSLAM) at the exchange. Data transfer rates of 8Mbits per
second are possible over a standard line operating alongside normal
telephone use of the same line.
32. The Internet itself is a set of ISP networks and noncommercial IP
networks which connect to one another, sometimes directly, but more
often via socalled Neutral Access Points (NAP), the main UK NAP
being the London Internet Exchange (LINX). Some smaller ISPs, which
lack the connectivity of others, buy access from larger ISPs, but the
bigger ISPs continue to interconnect by free mutual ‘peering’. Some
ISPs have no network of their own and resell the services of others.
Such ‘virtual ISPs’ include names like Virgin and Arsenal Football Club.
PST
N
Interne
t
Modem
ISP
Modem
Dat
a
N/W
DSLAM
Data
N/W
DSL modem
14
Chapter 2
Types Of Telecommunications Companies In The UK
1. Since opening up the telecommunications markets to competition in the
1980s, a wide range of companies have entered the market and many
have chosen to specialise in the kinds of network they have built and
services they offer.
2. The largest telephone network remains that run by BT which reaches
everywhere in the country (save for Hull, where Kingston
Communications operates). BT and Kingston have the Universal
Service Obligation, requiring them, in their respective areas, to provide
telephone service on request to anyone who wants it.
3. Many of the other networks use the BT network to connect with each
other, so they are still involved in the vast majority of calls made in the
UK, even if they start on a cable or mobile network.
4. Since their emergence in the 1980s/90s, there has been considerable
consolidation amongst the cable companies. Since 1991, the cable
companies have exploited their right to offer telephone service as well
as cable TV over their networks. There is one other cable company that
provides telephone service. Tweedwind provides service in the Isle of
Wight and parts of Cumbria, under the trading names of Isle of Wight
Cable and Omne.
5. There are 5 mobile networks in the UK, run by Vodafone, O
2
, Orange,
TMobile and the new 3
rd
generation network operator known as ‘3’.
There is also a specialist network operated by O
2
, known as Airwave,
which is used by the police, the fire service and in the future by the
ambulance service (and in principle other essential public services) for
their own internal radio communications.
6. There are a number of businessfocussed telecommunications
companies that have, to varying extents, built their own fibre networks.
These include Cable & Wireless, Energis, VERIZON BUSINESS, Thus,
COLT, Affiniti, Your Communications, Fibrenet and many other smaller
enterprises.
7. Recognising that it’s easier to build a core network, but harder to
replicate an access network, a range of companies have entered the
market providing socalled Indirect Access services. In its simplest
form, a BT customer dials an access code of the form 1xxx followed by
the wanted number. BT routes the call to the core network identified by
the access number and the other company completes the call,
including billing for it. A development of this service which has become
very popular in the last few years, is Carrier PreSelection (CPS). With
CPS, a BT customer opts to have all (or some) of his calls routed via a
stated indirect access company, so that no access code has to be
remembered or dialled. In case of problems, a CPS customer can use
the access code 1280 to have BT route the call. With both Indirect
Access and CPS, the customer still has to be a BT customer and pay
15
the BT line rental. Companies like Centrica (under both their British
Gas and OneTel brands) are active in this market.
8. A further development of telephony competition is also now emerging,
using ‘Wholesale Line Rental’. This is often structured like CPS, but in
this case, the competing company takes over the BT line and rents it
on behalf of the customer, so that the customer only has a single
relationship with the company.
9. The Internet service provision market has been competitive since it
emerged in the early 1990s – the pioneers being Pipex and Demon
(now owned by Thus). There are still hundreds of small ISPs in the UK,
including many ‘virtual ISPs’, but there has been considerable
consolidation and concentration in the market serving domestic
customers. The main players are now AOL (whose network serving the
UK is almost entirely in the USA), Wanadoo (mainly a virtual ISP
running on the Energis network and now owned by France Telecom),
BT, NTL and Telewest.
10. Broadband Internet is currently growing rapidly. Aside from NTL and
Telewest’s cable modem service on their own cable networks, most
customers’ broadband access is via their BT telephone line, using
Digital Subscriber Line technology. BT carries the broadband
connection over its own data network before handing over to the ISP
serving the customer.
11. A few ISPs have invested in ‘Local Loop Unbundling’ (LLU), whereby
they take over the BT line and use their own DSL equipment and data
network to provide service. The most successful operator to exploit
LLU is Easynet, although they only serve business customers.
12. A few companies offer Internet access via ‘Fixed Wireless Access’,
notably Pipex and UK Broadband. ‘Wifi’ radio technology has also been
used in a few rural locations to provide Internet access on a community
selfhelp basis, though this technology has primarily been used for in
building networking (increasingly within the home) and for ‘hotspot’
services in airports, hotels and coffee shops.
13. As mentioned before, IP is becoming the dominant technology.
Whereas in the past we dialled up over the telephone network to reach
the Internet, some Internet companies are now realising that
broadband Internet access can be used to provide voice services,
though in many cases in a form quite unlike the traditional PSTN.
Companies already wellknown in this market include Skype and
Vonage, but many more are now entering the market.
14. However, even mainstream telephone companies are expected to
convert their public telephony networks to IP technology in the next
decade. They won’t use the Internet as such to route calls, but their
own, more robust, managed IP networks. Such networks are often
described as Next Generation Networks (NGNs) and their development
will have implications for the resilience of the UK network.
16
Chapter 3
Threats To Continuity Of Service
1. We have become accustomed to the fixed telephone network always
being ‘up and running’, even when our local electricity supply is lost.
Indeed, this expectation creates frustration with the more recent mobile
and Internet networks which have been built on a more commercially
oriented basis.
2. All the major telephone companies have invested heavily in ensuring
the reliability of their networks and the continuity of services running
over them.
3. In this chapter, we will consider the many threats to continuity of
service that companies need to take into account. In summary, they
can be grouped into 5 headings:
· Physical
· Loss of key inputs
· System/Logical failings
· Software failures
· Electronic ‘interference’
Physical Threats
4. These include:
· Natural phenomena (Extreme weather, earthquake, flood and
lightning)?
· Fire
· Explosions, in particular those caused by gas leaks?
· Damage caused by accidents, vandalism, internal sabotage and
terrorism.
Loss of key inputs
5. Telecommunications depends on the continuous availability of many
‘key inputs’, amongst which the most critical are:
· Electrical Power
· Fuel (for backup generators and vehicle fleet)
· Human access (to operational installations)
· Materials
6. Electricity, in particular, is the most critical input. Not only is the
telecoms industry wholly dependant on electrical power, but the
electrical power industry depends on telecoms to manage their
extensive network of generators and grid distribution.
17
System/Logical failings
7. To prevent being vulnerable to the failure of a single part of the system,
telecommunications companies will invest, where practical, in duplicate
or triplicate backups for their equipment (redundancy) and diverse
transmission routings. Thus the ‘logical’ architecture of the service will
be more resilient than the simple physical layout. But sometimes, due
often to human error, these logical configurations can themselves fail to
provide the expected level of resilience. The key is to avoid, wherever
possible, ‘single points of failure’.
8. However, not all parts of the network can be made resilient and in
these cases, the complementary processes of restoration and repair
have to be strengthened.
Software failures
9. All telecommunications networks are reliant on software controlled
equipment, and no software is immune from errors and operational
failings. Unlike personal computers, it is not acceptable for a
telecommunications network to crash and stop responding altogether.
10. A particularly worrying form of software failure is called a ‘systemic’ or
‘commonmode’ failure, where a software error in one network node
causes the same fault to occur in other connected nodes, leading to a
‘runaway’ failure of an entire network.
Electronic ‘interference’
11. Telecommunications networks, especially those increasingly using IP
technology, can be vulnerable to conditions entering the system via the
network itself. Increasingly, these can be malicious in intent.
12. A wide range of types of threat fall into this category, including:
· Inappropriate signals injected by users, either too high a voltage or
at the wrong frequency?
· Similar signal pickup problems caused by radio interference, e.g.
from amateur radio transmissions?
· Traffic overloads, often stimulated by advertising campaigns and TV
based promotions?
· Denial of Service attacks – malicious attempts to damage a service,
sometimes by traffic overload, sometimes by the transmission of
‘malware’ (malicious software)?
· ‘Malware’, such as viruses, worms and Trojans?
· Hacking, including attempts to subvert the proper operation of the
billing system in networks?
· The transmission of specifically crafted signalling messages,
designed to cause misoperation of the network
18
Chapter 4
Resilience Measures Taken By Telecommunications Companies
1. Despite the long list of threats to which a telecommunications network
is exposed, as described in Chapter 3, in practice, there are many
mitigation measures that can be taken to reduce the risk that these
threats can pose. Although no network can ever be totally ‘nonstop’,
the performance of the UK telecommunications networks, especially
the public telephone networks, are very high.
2. This is not the appropriate document in which to record all the possible
and desirable countermeasures that can be taken, but the following
gives a flavour of the typical ways in which the telecommunications
networks are secured. Some residual difficulties are also mentioned.
3. Physical Threats: Exchange buildings are fitted with smoke, gas and
flood detectors. Some buildings will be physically hardened and be
fitted with CCTV monitoring. Building access is controlled by door entry
systems which can record who have entered the building. Internal
cellular security, as well as perimeter security may be used. Radio
masts are designed to cope with high wind and iceloading.
4. Loss of key inputs: Equipment will be secured against loss of electricity
both by having a battery backup (which might support service for about
an hour) plus a diesel generator designed to cut in when the public
mains supply fails. Because the large majority of home telephones are
powered by the telephone line itself, service can be provided even
when the domestic electricity is cut off. (Some domestic phones, such
as cordless phones and answering machines do need local mains
power, however).
Power: Generator backup is not practical to secure most mobile
network base stations or street cabinets in cable networks. This means
that in an extended electrical power outage, the mobile phone networks
may become subject to failure. Equally, the phones themselves rely on
battery recharging from the mains supply.
Fuel: The Fuel Crisis showed telecommunications operators are
vulnerable to loss of fuel. However, priority provision of fuel, alongside
other essential services should ensure continuation of critical business
functions.
Access to equipment: Similarly, the Foot & Mouth crisis and events
following city centre bombings have shown that if telecommunications
staff are denied access to their installations, then they may be unable
to assist the repair of equipment needed by other essential services.
Again, recognising priority of access is needed.
Stock: Many telecommunications companies hold as little stock of
material as they can, according to modern ‘justintime’ provisioning
principles. However, many make arrangements with their suppliers to
hold emergency stocks on their behalf.
19
5. System/Logical failures: This is an issue that has to be designedin
from the start. For example each concentrator can have diverse
routings to its host local exchange. Each local exchange is then
typically connected to 3 tandem/trunk exchanges. Each trunk exchange
is connected to every other. The result of this is that any two local
exchanges have a multitude of possible paths over which calls can be
set up, so the resulting network is extremely resilient to the loss of
either individual trunk exchanges or the transmission systems
connecting them. But any given customer will still be vulnerable to the
loss of his concentrator or local exchange. For this reason, BT
maintains a group of strategically positioned trailermounted exchanges
which can be deployed where necessary for fast restoration. Similarly,
replacement power equipment and generators can be deployed. All
telephone exchanges also use duplicated computers and switch paths
internally.
6. The UK Internet has not been planned as a single logical entity, which
is both a strength and a weakness. The Internet can often reconfigure
itself in times of outage. On the other hand, many parts of the Internet
rely on just a few buildings where different Internet providers both site
their equipment and make connections with one another.
7. Mobile networks are highly reliant on the fixed network operators to
connect their base stations and exchanges together. Hence, the mobile
network cannot be seen as a separate and alternative network to the
regular public fixed network. A similar situation arises with the Internet,
where the many smaller Internet Service Providers are dependant on
others for their transmission. Hence the whole UK telecommunications
infrastructure has significant elements of mutual dependency.
8. Software failures: Exchange equipment is designed to detect software
which is not working properly, contain the problem and restart the
offending subsystem. If all else fails, the entire exchange will
automatically restart. So unlike personal computers, they never stop
entirely. To avoid ‘common mode’ failures, some companies will
deliberately use two types of equipment in their network from different
suppliers, to avoid any ‘domino failures’.
9. Electronic ‘interference’: It has to be realised that no network has
enough spare capacity to cope with the increased demand for calls
which occur during major incidents. Traffic overloads in telephone
networks can cause major problems which can be avoided by invoking
traffic management techniques, such as ‘call gapping’ which reduces
the load on the system to one that can be safely managed. In some
circumstances, priority access to the networks can be provided to
ensure that appropriate public authorities can continue to function.
10. The Internet poses special threats because its original design concept
was to provide a very open and transparent form of network. This
means that all sorts of threats arise from inappropriate use or access of
the Internet. Unlike the telephone network, which has physical
separation of its customer connectivity and its control circuits, IP
networks have only a logical form of separation and this is vulnerable to
‘hacking’. Increasingly, IP networks are being protected by extensive
20
‘firewalls’ and progressively new protocols are being deployed to avoid
the threats caused by the originally highly open nature of the Internet.
11. IP networks do have their own strengths, however. For example,
because of the packetised nature of transmission and the fact that
these packets may traverse different paths across the network, it is far
harder to ‘eavesdrop’ on an Internet connection. Additionally, it is very
easy to encrypt messages before they pass over the Internet.
12. Not all parts of the network can be secured and the single access line
from the customer to the exchange is not capable of being protected
from failure economically. So customers are encouraged, where they
need higher than normal levels of security, to invest in two separated
paths from their building, perhaps to two different telephone
exchanges.
13. Telecommunications operators will invest in resilience commensurate
with the risk to their commercial interests, including their reputations. In
a competitive environment, where prices are constantly falling,
companies will often switch from competing on price to competing on
quality. Good resilience therefore becomes a competitive imperative.
and many of the desirable resilience features that government will wish
to see are often delivered by the operation of the market itself. But not
always. In particular, the mobile and Internet industries have arisen
from a quite different commercial culture than the telephony providers.
The Internet is commonly described as a ‘best efforts’ network.
14. There are particular risks as telephone companies move towards the
adoption of Next Generation Network IP technologies. The diversity of
the present network may be reduced and switching will be
concentrated in fewer nodes than at present. The telephone network
could start to suffer some of the weaknesses described above relating
to the wider Internet. Added to that, the introduction of any new
software driven technology is likely to cause some instability before the
inevitable software bugs are driven out.
21
Chapter 5
Statutory Provisions Concerning Telecommunications Resilience
There are a range of statutes that touch on telecommunications and in
particular the issues of resilience, emergency planning and wider national
security. Few of these provide clear powers to require all telecommunications
providers to maintain the resilience of their networks and services.
Furthermore, legal opinions within government are, to a degree, divided.
Some measures have been put in place by the industry on the understanding
that national security legislation could in the last resort be used to require it.
Others, however, believe that such legislation can only be used for reasons
directly relating to national security, i.e. the maintenance of public order and
the democratic rule of law. While the loss of major Critical National
Infrastructure could in extremis become a matter of national security, it is less
clear that national security legislation could be used to require all features that
assist the maintenance of the commercial and social activities of the country.
The Communications Act 2003
This Act, which replaced almost all of the former Telecommunications Act
1984, is the primary legislation that set up Ofcom as the regulator for the
broader communications industry and implemented the new European
regulatory framework which came into force in July 2003. Instead of the
former licensing regime of the Telecommunications Act, the new Act regulates
communications providers by means of general authorisations which are
required to be complied with as a condition of operating in the market.
In particular, Section 51 defines the subject matter that can be included by
Ofcom in the general Conditions of Entitlement. Section 51(1)(c) specifies
“conditions making such provision as OFCOM consider appropriate for
securing the proper and effective functioning of public electronic
communications networks” and thereby empowers Ofcom to implement Article
23 of the Universal Service Directive, entitled Integrity of the Network. It has
done so through Condition 3 of the Conditions of Entitlement:
3. PROPER AND EFFECTIVE FUNCTIONING OF THE NETWORK
3.1 The Communications Provider shall take all reasonably practicable steps to maintain, to the greatest
extent possible:
(a) the proper and effective functioning of the Public Telephone Network provided by it at fixed
locations at all times, and
(b) in the event of catastrophic network breakdown or in cases of force majeure the availability of the
Public Telephone Network and Publicly Available Telephone Services provided by it at fixed
locations, and
(c) uninterrupted access to Emergency Organisations as part of any Publicly Available Telephone
Services offered at fixed locations.
3.2 The Communications Provider shall ensure that any restrictions imposed by it on access to and use of a
Public Telephone Network provided by it at a fixed location on the grounds of ensuring compliance with
paragraph 3.1 above are proportionate, nondiscriminatory and based on objective criteria identified in
advance.
3.3 For the purposes of this Condition, “Communications Provider” means a person who provides a Public
Telephone Network at a fixed location and/or provides Publicly Available Telephone Services at a fixed
location.
22
Condition 3 only applies to providers of fixed telephony. It does not therefore
provide for any regulation of the resilience of mobile or Internet services.
Condition 3.2 goes slightly beyond the requirements of Article 23, but
continues a similar regulation contained in the old Condition 20 of the former
licence for Public Telecommunications Operators which was in force until July
2003.
Oftel, the predecessor of Ofcom, produced guidance for the industry on what
issues it expected should be considered when assessing whether companies
were complying with Condition 20. These are known as the “Essential
Requirements Guidelines” (published in October 2002) and while Ofcom no
longer wishes to act as author of such guidance, the material is currently
being revised as part of the Tripartite arrangements between the Cabinet
Office, BERR and Ofcom.
In practice, while Condition 3 impacts all telephony providers, as with most
regulation, there is no proactive compliance checking. Compliance action has
been restricted to events following a major network failure, for example, the
Southampton outage of 2002 and the Manchester fire of 2004.
However, compliance to the ‘Essential Requirements’ Guidelines was made
part of the voluntary elements within the National Emergency Plan for the UK
Telecommunications Sector (see Chapter 7).
23
Emergency Planning
Section 51(1)(e) specifies “conditions requiring or regulating the provision,
availability and use, in the event of a disaster, of electronic communications
networks, electronic communications services and associated facilities” and
thereby empowers Ofcom to implement conditions requiring providers to
assist central and local government in times of emergencies. This is
specifically allowed (though not mandated) by paragraph 12 of Annex A to the
Authorisation Directive and continues previous obligations on Public
Telephone Operators in their former licences.
Oftel published under 5.1(b) a list of emergency planning bodies in county and
unitary authorities, plus those central government departments with
emergency planning responsibilities.
Providers are not expected to seek out such departments, but will be
expected to respond appropriately when approached, either in advance, to
plan for some future contingency, or at the time of an event, such as a local
flood, storm etc.
The existence of this condition has assisted the voluntary production of the
National Emergency Plan for the UK Telecommunications Sector (see
Chapter 7).
Given that the previous licence condition only affected Public Telephone
Operators, it was deemed appropriate to limit the class of provider to whom
5. EMERGENCY PLANNING
5.1 Subject to paragraph 5.3, the Communications Provider shall, on the request of and in consultation
with:
(a) the authorities responsible for Emergency Organisations? and
(b) such departments of central and local government as Ofcom may from time to time direct for
the purposes of this Condition,
make arrangements for the provision or rapid restoration of such communications services as are
practicable and may reasonably be required in Disasters.
5.2 Subject to paragraph 5.3, the Communications Provider shall, on request by any person as is
designated for the purpose in any such arrangements, implement those arrangements in so far as is
reasonable and practicable to do so.
5.3 Nothing in this Condition precludes the Communications Provider from:
(a) recovering the costs incurred in making or implementing any such arrangements? or
(b) making the implementation of any such arrangements conditional upon being indemnified by
the person for whom the arrangements are to be implemented for all costs incurred as a
consequence of the implementation.
5.4 For the purposes of this Condition:
(a) “Communications Provider” means a person who provides a Public Telephone Network
and/or provides Publicly Available Telephone Services? and
(b) “Disaster” includes any major incident having a significant effect on the general public? and
for this purpose a major incident includes any incident of contamination involving radioactive
substances or other toxic materials.
24
this condition applies. However, by limiting it to telephone providers, it was
realised after the event that it does not apply to the two major suppliers of
transmission services to the broadcasters.
Section 132
Section 132 of the Communications Act provides powers for the Secretary of
State to direct Ofcom to suspend, in whole or in part, the authorisation of a
provider to provide networks or services, where he has reasonable grounds
for believing that it is necessary to do so to protect the public from any threat
to public safety or public health, or in the interests of national security. This is
permitted by Article 3 of the Authorisation Directive and flows from over
arching powers of Member States under Article 46(1) of the European Treaty.
Powers to restrict or limit providers’ services on the grounds of national
security have existed since the very beginning of telecommunications. Prior to
the new European regulatory framework, similar powers were included in SI
98/1580. As early as 1848, the Secretary of State used such powers to
prevent Chartists from coordinating their nationwide protest activities using the
telegraph system, which at the time was in private hands, using powers under
the Electric Telegraph Act of 1846.
Cutting off communications in times of national crisis is quite common
following coups and rebellions in other jurisdictions, but in today’s society, with
its loathing of censorship, it is difficult to see such powers ever being used in
peace time. Additionally, the powers are of their very nature restrictive and do
not provide for making orders for providers to provide positive assistance to
the government in times of emergency.
Telecommunications Act 1984
As mentioned above, the Communications Act repealed almost all of the
former Telecommunications Act of 1984, which had introduced competition,
privatized BT and set up Oftel.
However, paragraph 70 of Schedule 17 of the Communications Act 2003
amended Section 94 of the Telecommunications Act and this remains one of
the few sections of the former Act still in force. Section 94 allows the
Secretary of State to give directions to providers of public electronic
communications networks, or Ofcom, in the interests of national security, or of
relations with a foreign country. The directions are to be laid before
Parliament, unless the Secretary of State considers that disclosure is against
the interests of national security, or of relations with a foreign country, or the
commercial interests of some other person. The Secretary of State has
power to defray costs incurred in complying with any direction.
Civil Contingencies Act 2004
This recent piece of legislation updates the very antiquated Emergency
Powers Act of 1920, a statute so old that telecommunications was not
included at the time. This explains why the Emergency Planning obligations
have always been separately placed on providers, such as Condition 5
described above. Its definition of ‘emergency’ includes ‘disruption of a system
25
of communication’, though much of the thrust of the Act is to modernise the
ways in which bodies respond to emergencies at the local level.
Section 22 of Schedule 1 of the Act defines all network providers who supply
telephone services to be “Category 2 responders”. Such responders are
required to provide information to other emergency bodies and collaborate
with them on making contingency plans for all kinds of emergency. There has
been some concern that given the number of local committees to be set up to
do this at a local level, that it would represent an undue burden on a large
number of providers. In practice, providers are likely to represent one another
so that the burden is shared and minimised. There have been other concerns
that the duty to collaborate partly overlaps the obligations under Condition 5.
Condition 5 does go further however, in that it requires that network providers
not only plan but implement planned services on request.
If an Emergency is declared under Part 2 of the Act, then ministers would
have wide powers to direct bodies to do things, including anything required
under Section 22(2)(e) for the purpose of protecting or restoring a system of
communication. Under this Act, an Emergency is not the same as a Disaster
as used in Condition 5.
See definition and list of Category Two Responders in ANNEX 2.
Other Statutes
Although outside the primary scope of this document, it should be noted that
there are other Acts which impinge on communications providers and that the
above does not therefore represent the totality of the statutory or regulatory
burden on providers. In particular, in relation to national security and law
enforcement for serious crime, there are two Acts that relate to obligations on
lawful interception and the retention of communications data. Policy on these
matters rests with the Home Office.
The Regulation of Investigatory Powers Act 2000 (RIPA)
Lawful interception can only be carried out through warrants issued by a
Secretary of State to one of the 9 intercepting agencies listed at Section 6(2)
of the Act. Communications Providers are required to provide assistance to
these bodies when requested, subject to the request being reasonably
practicable (Section 11).
The AntiTerrorism, Crime and Security Act 2001
Implemented in the wake of ‘9/11’, this statute, in Part 11, requires
Communications Providers to retain communications data. However, it has
not been formally implemented and data retention continues to be promoted
and governed by a voluntary code of practice. Steps are currently being taken
to seek a harmonized European approach to data retention requirements.
Limitations
It is important to recognise that some threats to the telecommunications
network are global or external in character, so national legislation alone
26
cannot solve everything. However, there is extensive cooperation amongst UK
agencies with those in other countries with sympathetic objectives in respect
of national security.
27
Chapter 6
Roles of Government Departments, the Regulator and other
Agencies
Department for Business, Enterprise and Regulatory Reform (BERR)
The DTI has the primary policy responsibility for the telecommunications
industry, including regulatory matters. The Cabinet Office, while being the
main department for coordinating government policy on emergency planning,
relies on a system of lead government departments to oversee the delivery of
resilience within their areas of competence. In particular, DTI takes that lead
role for telecommunications and ensures that appropriate resilience
arrangements are in place. In practice, this is delivered through a Tripartite
arrangement between DTI, the Cabinet Office and Ofcom, with support from
specialist agencies such as NISCC and NSAC (see below).
Cabinet Office, Civil Contingencies Secretariat (CCS)
The CCS was set up in July 2001 to improve the UK's resilience against
disruptive challenges through working with others to anticipate, assess,
prevent, prepare, respond and recover. It defines resilience as the ability at
every level national, regional and local to detect, prevent and if necessary
handle disruptive challenges. These could range from floods, through
outbreaks of human or animal disease, to terrorist attacks.
Its objectives are to:
· lead horizon scanning activity to identify and assess potential and
imminent disruptive challenges?
· lead the delivery of improved resilience across Government and the
public sector?
· ensure that the Government can continue to function and deliver public
services during crisis? and
· improve the capability of Government and other stakeholders to
prepare for, respond to and manage potential challenges.
Cabinet Office, Central Sponsor for Information Assurance (CSIA)
The CSIA works with partners in the public and private sectors, as well as its
international counterparts, to help safeguard the nation's IT and
telecommunications services.
Its broad focus is on safeguarding IT systems but also has a specific remit
within the telecommunications area to identify and address vulnerabilities of
national telecommunications systems and progress their resolution in
conjunction with other government departments and organisations. CSIA also
coordinates a range of services and facilities for use in emergencies, such the
28
Government’s Emergency Communications Network, the Government
Telephone Preference Service and its mobile counterpart ACCOLC (Access
and Overload Control).
National Infrastructure Security Coordination Centre (NISCC)
Within the Government’s broad role to promote the protection of the Critical
National Infrastructure, NISCC’s role is to minimise the risk to the CNI from
electronic attack.
NISCC has no regulatory, legislative or law enforcement role? it seeks to
achieve its aim through four broad work streams:
· Threat Assessment. Using a wide range of resources to investigate,
assess and disrupt threats.
· Outreach. Promoting protection and assurance by encouraging
information sharing, offering advice and fostering best practice.
· Response. Warning of new threats? advising on mitigation? managing
disclosure of vulnerabilities? helping the CNI investigate and recover
from attack.
· Research and Development. Devising the most advanced techniques
and methods to support efforts across all work streams.
NISCC was set up in 1999 and is an interdepartmental centre drawing on
contributions from across government. Defence, Central Government Policy,
Trade, the Intelligence Agencies and Law Enforcement all contribute expertise
and effort.
National Security Advice Centre (NSAC)
NSAC is part of the Security Service and contributes to the protection of key
Government assets and the UK's Critical National Infrastructure (CNI),
including telecommunications, and to the reduction of their vulnerability to
terrorism and other threats. NSAC works with telecommunications providers
identifying those parts of their systems which represent a significant risk to the
CNI and can provide advice on physical and personnel protective security.
Office of Communications (Ofcom)
Ofcom is the regulator for the communications industry and assumed the
powers of the former regulators (such as Oftel) in December 2003. Unlike
Oftel, it is not a Government department, but a Public Corporation.
Ofcom’s role includes ensuring compliance by providers to their Conditions of
Entitlement, including Conditions 3 and 5 as described in Chapter 5. Ofcom
investigates major failures within the telecommunications system and provides
advice to DTI and the Cabinet Office as part of the Tripartite arrangements.
29
Chapter 7
Emergency Plans And Response Measures
However well telecommunications providers build their networks and systems,
the investment in resilience will always reflect the perceived risks, the known
vulnerabilities and the practicality of trying to protect assets against the
increasingly uncertain modes of attack by malicious parties. It is therefore
important that as well as building in resilience and other mitigating measures
against risks, there should be clear plans and response measures should
emergency situations arise.
Telecommunications providers have always worked with Emergency Planning
organisations in both central and local government to deliver support for
emergencies in the community.
Under CSIA’s chairmanship, the Telecommunications Industry Emergency
Planning Forum operates to two key documents:
· The National Emergency Plan for the UK Telecommunications Industry?
and
· The Memorandum of Understanding for cooperation in emergency
situations
There is also a nondisclosure agreement which protects any shared
information from being passed outside the emergency planning community.
The Emergency Plan contains information on emergency contact points
(which are regularly exercised), emergency scenarios (both those identified
within the industry and those communicated from Government), management
processes for handling emergencies and priority customers & services.
The Memorandum of Understanding allows the sharing of human and material
resources amongst providers when required in an emergency.
The Emergency Planning Forum continues to oversee the maintenance of
these documents and is working on further activities to identify risks and
improve resilience.
30
Annex 1 – Typical core network of a smaller operator
This kind of network could be provided either by selfbuild or by acquiring
dark fibre leases. In contrast, BT’s core network reaches every city, town
and many villages in the entire country and their access network serves
almost every building.
Exeter
Bristol
Reading
Portsmouth
Dover
Lowestoft
Milton Keynes
Leicester
Sheffield
Newcastle
Manchester
Birmingham
Edinburgh
Berwick
Middlesborough
Preston
Carlisle
Newbury
Swindon
Basingstoke
Brighton
Glasgow
Leeds
31
ANNEX 2
Civil Contingencies Act 2004, Definition of Category Two Responder
22 (1) A person who provides a public electronic communications
network which makes telephone services available (whether for
spoken communication or for the transmission of data).
(2) In subparagraph (1)
(a) the reference to provision of a network shall be construed
in accordance with section 32(4)(a) and (b) of the
Communications Act 2003 (c. 21), and
(b) "public electronic communications network" shall have the
meaning given by sections 32(1) and 151(1) of that Act.
List of Telecoms Category 2 Responders
1
Company Type of Service
Affiniti
2
Fixed
BT Fixed
Cable & Wireless Fixed
COLT Fixed
Global Crossing Fixed
3 Mobile
Kingston Communications Fixed
Level 3 Fixed
NTL
3
Fixed
O
2
Mobile
Orange Mobile
T Mobile Mobile
Telewest Fixed
Thus Fixed
Vodafone Mobile
Verizon Business Fixed
1
Comprising major companies that (as defined under the CCA) provide a public
electronic communications network which makes telephone services
available (whether for spoken communication or for the transmission of data).
2
Affiniti is part of the Kingston Communications Group.
3
NTL and TeleWest are in merger discussions.
32
Glossary
ACCOLC Access and Overload Control, a system designed to give
priority access to mobile networks in times of stress.
AOL America On Line – a major USbased Internet Service
Provider
ATM Asynchronous Transfer Mode, a system for high speed data
transmission.
Base Station The part of a mobile telephone network where the radio
antenna is sited.
CCS Civil Contingencies Secretariat, part of the Cabinet Office
which coordinates civil emergency matters.
CCTV Closed Circuit Television
CNI Critical National Infrastructure, the key assets, services and
systems that support the economic, political and social life of
the UK.
CPS Carrier PreSelection, a service whereby telephone
customers can have their calls routed via another network
without having to dial a specific code.
CSIA Central Sponsor for Information Assurance, part of the
Cabinet Office, which has a coordinating role in telecoms
resilience matters.
DSL Digital Subscriber Line, a technology which allows a normal
telephone line to carry broadband data.
DP Distribution Point, the final part of the local access network
where connections are made to individual homes, often
mounted on a telegraph pole.
FDDI Fibre Distributed Data Interface, a system for high speed
data transmission over fibre, typically across campus sites.
Frame Relay A medium speed system for data transmission, often used
within corporate networks.
Gbit/s Gigabits per second, that is, a data transmission rate of 10
9
bits per second.
GTPS Government Telephone Preference System, a facility
whereby priority can be given to public authorities on the
fixed telephone network.
33
Head End The central building in a cable network where the TV signals
are distributed.
Internet A global system of Interconnected Networks, using a
common technical basis.
Intranet An internal, corporate network using the same IP protocols
as the Internet.
IP Internet Protocol, the base protocol used for data
transmission on the Internet.
ISP Internet Service Provider
LINX The London Internet Exchange, were ISPs connect their
networks together to exchange traffic.
LLU Local Loop Unbundling, a facility whereby a telecoms
provider can use the copper loops of the BT network to
provide their own competing broadband data services.
MDF Main Distribution Frame, an arrangement of connections
assembled on a large gantry which allows the external
copper circuits to be crossconnected to any piece of
internal equipment in an exchange building.
NAP Neutral Access Point, such as the LINX, where ISPs
connect their systems together.
NGN Next Generation Network, a multiservice network mainly
based on IP technology which is set to replace the present
telephone network.
NISCC National Infrastructure Security Coordination Centre, a
crossdepartmental agency which focuses on electronic
security of the CNI.
NSAC National Security Advice Centre, part of the Security Service
that specialises in physical security.
Ofcom Office of Communications, the UK communications
regulator.
Oftel Office of Telecommunications, the former telecoms regulator
19842003.
PCP Primary CrossConnect Point, typically a green roadside
cabinet where local copper cables are crossconnected.
Private Circuits Sometimes called Leased Lines, these are pointtopoint un
switched telecoms circuits, used by businesses and other
providers to link sites together on a permanent basis.
PSTN Public Switched Telephone Network, the ordinary phone
34
network.
SMDS Switched MultiMegabit Data Service, a system of high
speed data transmission, a precursor to ATM.
WiFi Wireless Fidelity, a radio system used for connecting
computers together over short distances, in homes, offices
or at public ‘hotspots’.
WLR Wholesale Line Rental, a service whereby a competitor to
BT provides telephone service by reselling the BT network,
in a similar way that ‘airtime providers’ provide service over
mobile networks.
X25 A system of medium speed data transmission which has
now largely been replaced by IP.
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