10 December 2001

Summary

Chapter one – Introduction

Chapter two – The Essential Requirements Task Group

Chapter three – The Essential Requirements Guidelines

Chapter four – The criteria for restriction of network access

Chapter five –Next steps

Annex A – Licence Condition

Annex B – Draft text of the guidelines on the essential requirements for network security and integrity

Annex C – Draft text of the criteria for the restriction of access to and use of the fixed public telephone system on the Grounds of Network Security or Integrity

Annex D – Glossary

Summary

S.1 This consultation document presents draft Guidelines on the interpretation of the network security and integrity provisions of Condition 20 of the Public Telecommunications Operators’ Licence. It also presents the draft of a set of criteria for restriction of access to the network on the grounds of network security and integrity, as cited in the same Licence Condition.

S.2 The draft Guidelines on the Essential Requirements for Network Security and Integrity, normally referred to throughout this consultation document simply as the Guidelines, are based on the output from the Essential Requirements Task Group (ERTG) of the Network Interoperability Consultative Committee (NICC). The NICC is an industry committee set up to advise the Director General on interoperability issues and to provide guidance to standards bodies on such issues. The draft Criteria for the Restriction of Access to and Use of the Fixed Public Telephone System on the Grounds of Network Security or Integrity, elsewhere referred to simply as the Criteria, were also prepared by the ERTG. The ERTG was set up by the NICC in response to Oftel’s July 2000 request for advice on the network security and integrity provisions of Condition 20. The ERTG delivered drafts of the Guidelines and Criteria to the NICC in July 2001 and October 2001 respectively. These documents were accepted by the NICC for onward transmission to Oftel, subject to the understanding that a public consultation on both documents would be carried out.

S.3 Oftel has made some modifications to these drafts for reasons explained in the consultation document, particularly in relation to the addition of the so-called ‘life-line’ requirements to the draft Guidelines, which include requirements for line-powering of end-user equipment in certain circumstances.

S.4 At the time of publication, it is clear that the risk environment has changed due to global events, in terms of risk both to commercial interests and to wider public interests. In Oftel’s view, this does not change the guidance contained in these documents, but it will change the degree to which operators will wish to implement security measures. Oftel will continue to give emphasis to network security in general, and to compliance with these Guidelines in particular.

S.5 Oftel is now seeking comments on both the draft Guidelines and the draft Criteria. This consultation process is primarily aimed at members of the Industry, however consumer groups will particularly wish to note the line-powering issue referred to above, and reflected in question four of the consultation. Having considered comments received during the consultation process, Oftel will adopt and publish final versions of these documents. Oftel will then use the Guidelines and Criteria as appropriate in the event of disputes or policy debates in relation to the network security or integrity requirements of Condition 20, or in relation to the restriction of network access on these grounds.

S.6 Chapter one of this document sets out the background to this consultation, and the relevant requirements of PTO Licence Condition 20. Chapter two explains the history and method of working of the ERTG. Chapter three introduces the draft Guidelines. Chapter four introduces the draft Criteria. Chapter five contains the details of the consultation process and a summary list of the questions that Oftel is asking stakeholders.

S.7 The annexes contain the draft text of the Guidelines and Criteria on which Oftel is consulting, along with the text of Licence Condition 20 and a glossary of terms, abbreviations and references.

Chapter one – Introduction

Background

1.1 'Essential Requirements' are so-called because they are non-market requirements that must be delivered in recognition of the important role that telecommunications plays in the wider economic and social well-being of a country.

1.2 There has been an Essential Requirements condition (now Condition 20) in public telecommunications operators’ licences since July 1998 (see ‘Legal framework’ below). The licence condition refers to the Licensee taking "all reasonably practicable steps to maintain to the greatest extent possible" network security and network integrity. However, these terms are not defined in the licence condition nor in the Revised Voice Telephony Directive 98/10/EC (RVTD)[1] from which these requirements stem.

1.3 Additionally, the licence condition requires that any restrictions imposed by the Licensee on access to the Fixed Public Telephone System on the grounds of network security or network integrity are proportionate, non-discriminatory and based on objective criteria identified in advance. Once again, neither the licence condition nor the RVTD [1] provides clear statements on who should create these objective criteria. Oftel has noted that no operator has yet published any such criteria.

1.4 Therefore, in the absence of guidance elsewhere, Oftel has set up a project to produce and publish Guidelines on the network security and integrity requirements in Condition 20, along with criteria for the restriction of network access on the grounds of network integrity or security. Oftel is not taking this action because it is aware of major shortfalls in network security currently, but is doing so simply to address this gap in guidance. Oftel considers that there should be a common understanding between Oftel and the industry of what might represent appropriate measures to protect network security and integrity, and what actions an operator might legitimately take to restrict network access in pursuit of this goal. Oftel will continue to monitor and investigate compliance to Condition 20, proactively seeking extra information and taking enforcement action if needed. Oftel will also take suitable action to ensure the provisions of any new European Directives in this area are taken into account.

1.5 The purpose of this consultation is to obtain comments from stakeholders on the draft Guidelines and Criteria that Oftel has produced in conjunction with the Industry. As a result of this consultation process, Oftel expects to adopt and publish final versions of these documents. Any resulting Guidelines will be non-binding on the Director General and will not fetter the Director General’s discretion.

1.6 In this document, the term ‘network security’ is used to refer to protecting the availability of the network and services from threats due to the inherent reliability of the network, and its vulnerability to hazards such as weather, natural disaster and malicious acts

1.7 ‘Network integrity’ concerns threats to the normal operation of the network that enter via the network itself, and also those that are introduced from outside sources such as customers or other networks. Examples of such threats include electrical conditions, signalling and traffic loads.

Legal framework

1.8 Article 13 of the RVTD [1] identifies five ‘essential requirements’ that apply to all fixed public telephone networks and fixed public telephone services:

• the first essential requirement in the RVTD is the security of network operations. The RVTD requires that Member States take all necessary steps to ensure the availability of fixed public telephone networks and services in the event of catastrophic network breakdown or force majeure such as earthquake, flood and fire;
• the second essential requirement in the RVTD is the maintenance of network integrity. The RVTD requires that Member States take all necessary steps to ensure that the integrity of the fixed public telephone network is maintained;
• the RVTD also states that National Regulatory Authorities must ensure than any restrictions on access to and use of the fixed public telephone network on the grounds of network security or integrity are non-discriminatory and based on objective criteria identified in advance; and
• the remaining three essential requirements identified in the RVTD (which relate to interoperability of services, protection of data and effective use of the frequency spectrum) are beyond the scope of this consultation.

1.9 The RVTD was transposed into UK law by the RVTD Regulations [2], and thence into Licence Condition 20 of the Public Telecommunications Operator (PTO) licence. In particular, the relevant Licence Conditions for the purposes of this consultation are:

• Condition 20.3, which requires the licensee to take "all reasonably practicable steps" to maintain availability in the event of catastrophic network failure or force majeure (eg fire, earthquake or flood);
• Condition 20.4, which requires the licensee to take "all reasonably practicable steps" to maintain integrity against malfunctions caused by electrical conditions, signalling protocols or traffic loads; and
• Conditions 20.5 and 20.6, which relate to restrictions on access to the network on grounds of network security or integrity;

1.10 The full text of Condition 20 of the PTO licence can be found at Annex A.

Scope

1.11 This consultation relates to the essential requirements for network security and integrity only, and to criteria for restricting network access on the grounds of network security and integrity. The other essential requirements (relating to interoperability, data protection and effective use of the frequency spectrum) are beyond the scope of this consultation.

1.12 Both the Guidelines and the Criteria will apply to Fixed Public Telephone Systems and Fixed Publicly Available Telephone Services only and are independent of the technologies used to deliver these services. For the avoidance of doubt, these could include IP or other packet-based systems if used to deliver Fixed Publicly Available Telephone Services. The terms Fixed Public Telephone System and Fixed Publicly Available Telephone Service are defined in the PTO licence.

1.13 The guidance in these documents is not intended to define the requirements that may be placed on operators by government in times of a national emergency or in order to protect national security. This is the responsibility of other government departments, principally the Cabinet Office, and queries on these requirements should be addressed to them.

Question 1 – Do you agree that it is appropriate for Oftel to publish guidelines on the network security and integrity provisions of Condition 20 of the PTO Licence?

Question 2 – Do you agree that it is appropriate for Oftel to publish example criteria for the restriction of network access on the grounds of network security or network integrity?

Chapter 2 – The Essential Requirements Task Group

2.1 In July 2000, Oftel asked the NICC to advise the Director General on:

• the publication of guidelines on the network security and integrity essential requirements licence condition, and
• objective, proportionate, non-discriminatory and industry-agreed criteria for restriction of access to the network on the grounds of network security or network integrity.

2.2 In making this request, Oftel acknowledged that the NICC does not usually undertake operational work. However, Oftel anticipated that the strong technical aspect to the Essential Requirements project meant that the NICC would wish to be involved.

2.3 The Operator Policy Forum (OPF) was also briefed on the Essential Requirements project at its meeting on 30 May 2000.

2.4 In response to Oftel’s request, the NICC set up the Essential Requirements Task Group (ERTG), which held its first meeting in September 2000. Membership of the ERTG was open to:

• the Public Network Operators Interest Group (PNO-IG) of the NICC (representing both fixed and mobile public network operators),
• the Special Systems and Public Equipment Interest Group (SSPE-IG) of the NICC (representing manufacturers of public network exchanges and associated equipment) and
• interested government departments.

2.5 Concerns were expressed at the second meeting of the ERTG in October 2000 that some affected operators might not have been aware that the ERTG had been set up. As a result of these concerns, Oftel sent a letter in October 2000 to all UK operators providing direct access to customers that were not already represented at the ERTG. The letter alerted them to the existence of the ERTG and invited them to attend the next meeting.

2.6 The ERTG delivered a draft of the Guidelines to the NICC in July 2001 and draft Criteria in October 2001. The NICC approved these documents and forwarded them to Oftel, subject to the proviso that there would be a period of consultation when further comments could be made. Oftel considers that the present consultation meets the requirements of the NICC in this respect.

2.7 Oftel would also like to take this opportunity to record its thanks to the NICC and in particular the members of the ERTG for their extremely valuable contribution to the production of the draft Guidelines and Criteria.

Chapter 3 – The Essential Requirements Guidelines

Note –The paragraph numbers of the draft Guidelines referred to in this chapter are those of the draft Guidelines document as it appears at Annex B in this consultation document.

3.1 The ERTG’s Draft Guidelines on the Essential Requirements for Network Security and Integrity were accepted by the NICC in July 2001, subject to the understanding that there would be an opportunity for further comments during a period of consultation.

3.2 Oftel has made four changes to the Draft Guidelines since they were accepted by the NICC:

• the title of the document has been changed from Draft Guidelines on the Essential Requirements to Guidelines on the Essential Requirements for Network Security and Integrity, to clarify that the Guidelines only cover the network security and integrity essential requirements;
• paragraphs BA3 to BA7 in Annex BA (which summarises the existing regulatory framework for terminal equipment) have been modified to more accurately reflect the provisions of the Radio Equipment & Telecommunications Terminal Equipment Directive[3];
• a ‘Note on Annexes BB and BC’ has been added to the document just before Annex BB (see explanation below); and
• ‘Requirements for Lifeline Telephony’ have been added to the document at Annex BC.

3.3 Oftel acknowledges that both Annex BB and Annex BC could be considered beyond the scope of the Guidelines, since they relate to compliance with the requirements on operators to provide access to the Emergency Service. However, it is clearly beneficial to publish the information in Annexes BB and BC more widely, and Oftel considers that the Guidelines are a suitable vehicle for doing this. Oftel would also point out that both Licence Condition 20.3 and Licence Condition 20.4 require the Licensee to have ‘particular regard to the needs of Emergency Organisations’. Some parts of Annex BB and Annex BC should be considered as part of the Guidelines, in so far as they describe how Oftel would expect the Licensee to meet this ‘particular regard’ requirement. The ‘Note on Annexes BB and BC’ has therefore been added to clarify their status.

3.4 Oftel is aware that the information in Annexes BB and BC of the draft Guidelines, although widely understood and acknowledged, has yet to be formally recorded. Oftel originally documented the ‘lifeline’ requirements in Annex BC in response to a request received in the context of work on local loop unbundling (LLU). However these are long-standing requirements that access operators have always met in relation to the obligation to provide access to the 999/112 emergency services and to operator assistance.

3.5 During initial consultation with potential LLU operators, it became clear to Oftel that some operators have difficulty with the line powering requirements for one or two line telephony when delivered over digital subscriber line (DSL) technology. This is because battery backup in the event of a mains power failure for DSL telephony equipment located at the customers’ premises could potentially be onerous. However, without battery backup, the customer would have no alternative means of accessing the 999/112 Emergency Service (there are of course other types of customer premises equipment that may not work in the event of mains power failure, such as fax machines and DECT cordless phones. However, in these cases, the customer’s line is still capable of handling an emergency call using an ordinary telephone handset. With a DSL-telephony enabled line, this would not be possible).

3.6 Oftel therefore seeks the views of all interested parties about whether there should be any relaxation in the area of line powering requirements for one and two line telephony.

3.7 The full draft text of Oftel’s Guidelines on the Essential Requirements for Network Security and Integrity is at Annex B.

Question 3 – What comments do you have on the draft Guidelines on the Essential Requirements for Network Security and Integrity presented in this document?

Question 4 – What comments do you have on the line powering requirement for one or two line telephony as described in Annex BC of the draft Guidelines on the Essential Requirements for Network Security and Integrity? If this requirement were to be relaxed, would it be sufficient as an alternative to warn consumers of the possible impact at the time of installation?

Chapter 4 – The Criteria for Restriction of Network Access

Note – The paragraph numbers of the draft Criteria referred to in this chapter are those of the draft Criteria document as it appears at Annex C in this consultation document.

4.1 The ERTG’s Example Criteria For The Restriction Of Access To The Fixed Public Telephone System were accepted by the NICC in July 2001, subject to the understanding that there would be an opportunity for further comments during a period of consultation.

4.2 Oftel has made one change to the Example Criteria since they were accepted by the NICC:

• the title of the document has been changed from Example Criteria For The Restriction Of Access To The Fixed Public Telephone System to Criteria For the Restriction of Access to and Use of the Fixed Public Telephone System on the Grounds of Network Security or Integrity. The word ‘example’ has been removed because it is Oftel’s intention (once these criteria are formally adopted) to assume network operators are using them if network operators have not identified their own criteria in advance. The other changes to the title have been made to reflect the phrasing used in PTO Licence Condition 20.

4.3 The full draft text of to Criteria For the Restriction of Access to and Use of the Fixed Public Telephone System on the Grounds of Network Security or Integrity is at Annex C.

4.4 As was pointed out earlier in this consultation document, these criteria are referred to in licence condition 20, which in turn gives effect to the relevant part of the RVTD. In keeping with the aim of proportionality in regulatory obligations and consistent with Oftel’s strategy of appropriate regulation, Oftel believes this criteria document strikes a reasonable balance between ensuring the aims of the directive are met whilst ensuring that the limitations to access are kept to those that are strictly necessary. A key factor in achieving this balance has been the close involvement by network operators in developing the Criteria. The outcome reflects their considered view and not that of any particular operator. Given that the operators have to bear any costs of excessive restrictions, Oftel believes the process used to develop the Criteria provides the necessary safeguards that the criteria are not overly burdensome.

4.5 At the time of writing, Oftel is consulting separately on co-mingling of equipment and arrangements for access to MDF sites in the context of local loop unbundling. For the avoidance of doubt, Oftel considers that the guidance contained in the Criteria is not in any way inconsistent with nor does it pre-judge the outcome of the co-mingling and access consultations.

Question 5 – What comments do you have on the draft Criteria For the Restriction of Access to and Use of the Fixed Public Telephone System on the Grounds of Network Security or Integrity presented in this document?

Question 6 – Do you agree that it is appropriate for Oftel to assume network operators are using these criteria if network operators do not identify their own criteria in advance?

Chapter 5 – Next Steps

Details of consultation

5.1 Oftel is publishing this consultation document so that interested parties may comment on the issues which it addresses. The closing date for submitting comments is 11 March 2002. On this occasion, Oftel is also inviting interested parties to comment on the responses made by others (see below for publication arrangements). The closing date for these ‘comments-on comments’ is 25 March 2002.

5.2 Where possible, comments, and comments-on-comments, should be made in writing and sent by e-mail to keith.bowman@oftel.gov.uk. However, copies may also be posted or faxed to the address below. If any interested parties are unable to respond in one of these ways, they should discuss alternatives with the Oftel manager named below:

Keith Bowman
Senior Technical Advisor
Oftel
50 Ludgate Hill
London
EC4M 7JJ

tel: 020 7634 5348
fax: 020 7634 8893

Further copies of this document

5.3. This document can be viewed in the Publications section of Oftel’s website (www.oftel.gov.uk), under classification Industry Guidelines. Paper copies and more accessible formats such as large print, Braille, disc and audio cassette can be made available on request. Please contact Oftel’s Research and Information Unit by phoning 020 7634 8761 or by sending an e-mail to infocent@oftel.gov.uk.

Publication of comments made by stakeholders

5.4. In the interests of transparency, all non-confidential comments and comments-on-comments, will be published. Respondents should separate out any confidential material into a confidential annex which is clearly identified as containing confidential material. Oftel will take steps to protect the confidentiality of all such material from the moment that it is received at Oftel’s offices. However, in the interests of transparency, respondents should avoid applying confidential markings wherever possible.

5.5 Non confidential responses can be viewed on Oftel’s website in the Publications section under Responses to Oftel consultations. They can also be viewed at Oftel’s Research and Information Unit. Appointments must be made in advance by phoning 020 7634 8761 or sending an e-mail to infocent@oftel.gov.uk.

e-mail notifications

5.5 Oftel has a free e-mail based mailing list to help people stay informed about the work that Oftel is doing. Each time an Oftel document is published and placed on Oftel’s website at www.oftel.gov.uk, subscribers to the list receive an e-mail alert. To register, please go to the What’s New section of the website and link to the electronic form.

Final statement

5.8 Oftel will prepare a final statement, having considered stakeholders’ responses to this consultation. This statement will contain final versions of the Guidelines and Criteria as adopted by Oftel.

Summary of questions

Question 1 – Do you agree that it is appropriate for Oftel to publish guidelines on the network security and integrity provisions of Condition 20 of the PTO Licence?

Question 2 – Do you agree that it is appropriate for Oftel to publish criteria for the restriction of network access on the grounds of network security or network integrity?

Question 3 – What comments do you have on the draft Guidelines on the Essential Requirements for Network Security and Integrity presented in this document?

Question 4 – What comments do you have on the line powering requirement for one or two line telephony as described in Annex BC of the draft Guidelines on the Essential Requirements for Network Security and Integrity? If this requirement were to be relaxed, would it be sufficient as an alternative to warn consumers of the possible impact at the time of installation?

Question 5 – What comments do you have on the draft Criteria For the Restriction of Access to and Use of the Fixed Public Telephone System on the Grounds of Network Security or Integrity presented in this document?

Question 6 – Do you agree that it is appropriate for Oftel to assume network operators are using these criteria if network operators do not identify their own criteria in advance?

The consultation criteria

Oftel considers that this document meets the Cabinet Office code of practice on written consultation documents. The code is reproduced below for convenience. If you have any comments or complaints about this consultation process please contact:

Oftel Co-ordinator for the code of practice:

Rob Jex
Oftel
50 Ludgate Hill
London
EC4M 7JJ

tel: 020 7634 5350
fax: 020 7634 8943

e-mail: rob.jex@oftel.gov.uk

1) Timing of consultation should be built into the planning process for a policy (including legislation) or service from the start, so that it has the best prospect of improving the proposals concerned, and so that sufficient time is left for it at each stage.

2) It should be clear who is being consulted, about what questions, in what timescale and for what purpose.

3) A consultation document should be as simple and concise as possible. It should include a summary, in two main pages at most, of the main questions it seeks views on. It should make it as easy as possible for readers to respond, make contact or complain.

4) Documents should be made widely available, with the fullest use of electronic

means (though not to the exclusion of others), and effectively drawn to the attention of all interested groups and individuals.

5) Sufficient time should be allowed for considered responses from all groups with an interest. Twelve weeks should be the standard minimum period for consultation.

6) Responses should be carefully and open-mindedly analysed, and the results made widely available, with an account of the views expressed, and reasons for decisions finally taken.

7) Departments should monitor and evaluate consultations, designating a consultation co-ordinator who will ensure that all the lessons are disseminated.

Annex A – Licence Condition 20

Condition 20

ESSENTIAL REQUIREMENTS AND ESSENTIAL PUBLIC INTERESTS

20.1 The Licensee shall comply with any decision taken in accordance with the procedures referred to in regulation 21(1) of the Revised Voice Telephony Regulations which relates to proceedings to which the Licensee is a party, subject to regulation 21(2).

20.2 The Licensee shall comply with any notice served on it pursuant to regulation 21(6)(a) of the Revised Voice Telephony Regulations.

20.3 The Licensee shall take all reasonably practicable steps to maintain, to the greatest extent possible, the availability of Fixed Public Telephone Systems run by it and Fixed Publicly Available Telephone Services provided by it, having particular regard to the needs of Emergency Organisations, in the event of catastrophic network failure, or in cases of force majeure, such as extreme weather, earthquake, flood, lightning or fire.

20.4 The Licensee shall take all reasonably practicable steps to maintain, to the greatest extent possible, the integrity of Fixed Public Telephone Systems run by the Licensee and Fixed Publicly Available Telephone Services provided by it, having particular regard to the needs of Emergency Organisations; that is to say, protection of the physical and functional operation of such systems and services against malfunctions or failure caused by electrical conditions, signalling protocols or traffic loads conveyed from telecommunication systems connected to the Applicable Systems.

20.5 The Licensee shall ensure that any restrictions imposed by it on access to and use of its Fixed Public Telephone System on grounds of maintenance of network integrity, in order to protect, inter alia, network equipment, software or stored data are kept to the minimum necessary to provide for normal operation of the System.

20.6 The Licensee shall ensure that any restrictions imposed by it on access to and use of its Fixed Public Telephone System on the grounds of network security or network integrity are proportionate, non-discriminatory, and based on objective criteria identified in advance.

20.7 The Licensee shall take all necessary steps in order to maintain so far as practicable the highest level of Fixed Publicly Available Telephone Services provided by it to meet any priorities specified by the Director.

20.8 The Licensee shall not impose any restrictions on the use of any Terminal Equipment relating to Fixed Publicly Available Telephone Services provided by it on the grounds of interoperability of services where such equipment complies with the Terminal Equipment Regulations on the grounds of interoperability of services.

20.9 The Licensee may impose conditions on access to and use of its Fixed Public Telephone System on the grounds of protection of data only in accordance with Relevant Data Protection Legislation.

Annex B – Draft Text of the Guidelines on the Essential Requirements for Network Security and Integrity

Guidelines on the Essential Requirements for Network Security and Integrity

Introduction

Purpose

B.1 The purpose of these Guidelines is to ensure that the industry has a full understanding of Oftel’s approach to interpretation of Condition 20 in the fixed Public Telecommunications Operator (PTO) licence covering the "essential requirements", thus helping to protect the public interest and promote fair, efficient and sustainable competition.

Scope of Guidelines

B.2 These Guidelines contain an explanation of how Oftel will approach the enforcement of the following parts of Condition 20 of the fixed PTO licence:

B.3 Conditions 20.5 and 20.6, which relate to restrictions on access to the network on grounds of network security or integrity, will be addressed by separate guidelines. Conditions 20.8 and 20.9, relating to Terminal Equipment (TE) interoperability and data protection, are outside the scope of these Guidelines, although these Guidelines do encompass TE insofar as it poses a risk to network integrity.

Legal status of the Guidelines

B.4 These Guidelines do not affect the scope of the licence conditions listed in this section or any others. The Director General will take the Guidelines into account in applying the relevant conditions in licences, and give reasons if they are departed from. The Director General cannot legally fetter his discretion and retains the ability to depart from the Guidelines where the circumstances warrant it. The Guidelines are therefore not legally binding on the Director General.

B.5 These Guidelines will be subject to review and amendment following consultation with interested parties in the light of experience of their operation, of development in telecommunications markets and of any changes to UK or European Community law.

Background

B.6 The Revised Voice Telephony Directive [B1] Articles 13(1), 13(2)(a) and 13(2)(b) place obligations on Member States to ensure security of network operations and maintenance of network integrity. Additionally, any restrictions on network access on these grounds must be based on objective criteria identified in advance. These requirements apply to fixed public telephone network operators. In the UK, these articles have been transposed by the Revised Voice Telephony Regulations [B2] into fixed network operator’s licence as Conditions 20.3, 20.4, 20.5 and 20.6. These licence conditions apply whether or not the fixed network operator has significant market power. In addition, the licence requires the licensee to have particular regard to the needs of Emergency Organisations. The term Emergency Organisation is defined in the PTO licence.

Application

B.7 These Guidelines apply to Fixed Public Telephone Systems and Fixed Publicly Available Telephone Services and are independent of the technologies used to deliver these services. For the avoidance of doubt, these could include IP or other packet-based systems. The terms Fixed Public Telephone System and Fixed Publicly Available Telephone Service are defined in the PTO licence.

Acknowledgement

B.8 The Director General acknowledges the assistance given by the Network Interoperability Consultative Committee (NICC) in the production of these Guidelines.

Guiding Principles

B.9 To comply with Licence Conditions 20.3 and 20.4, Oftel expects network operators to adhere to the following over-arching principles:

Network Security

B.10 Network security relates to threats to the network due to the inherent reliability of the network itself, and its vulnerability to threats, for example weather, natural disaster and malicious acts. Oftel recognises that the source of threat may stem from an interconnected telecommunications network. In this section, Oftel seeks to indicate examples of areas that should be given attention, rather than specifying explicit targets for percentage availability, mean time between failures (MTBF), mean time to repair (MTTR) etc.

Physical Security

B.11 A secure environment is a key factor in the maintenance of an adequate telecommunications service.

B.12 Wherever reasonable, essential equipment should not be concentrated, particularly in one building, to the extent that overall network security is jeopardised. Where essential equipment is co-located (for example, multi-processor sites), priority should be given to physical separation such as a fire break to reduce the possibility of common mode failure.

B.13 Underground line plant, buried at a depth where intrusions are unlikely, is preferable to aerial line plant.

B.14 The location of all external line plant such as underground and aerial cables should be notified to the relevant authorities as and when appropriate.

B.15 Suitable processes should be in place to co-ordinate the activities of the various utilities and highway authorities to ensure that risk of damage is minimised.

B.16 All sites, including radio mast sites, need to be secured against malicious attack and other forms of physical interference. Sites should also be capable of withstanding relevant environmental conditions.

B.17 Where appropriate, diverse cable entry points, eg to sites or buildings, should be provided.

B.18 Where appropriate, use should be made of diverse duct tracks or routes.

B.19 Public telephone boxes should be positioned to minimise risk, for example from road accidents or vandalism. Street furniture such as cabinets should be similarly positioned and also be locked or sealed.

B.20 Poles should ideally be placed in the lowest risk positions consistent with their use. Aerial cables and dropwires must be installed to ensure adequate clearance of vehicles, land and buildings (see Section 10 of the Telecommunications Code [B3]). A procedure for regularly surveying poles to ensure their physical integrity and to assess new risks, eg tree growth, should be in place.

B.21 The power supply to key equipment should not be interrupted in the event of a mains power supply failure.

B.22 The mains supply should be secure and steps taken to ensure that it is reliable. Where appropriate duplication should be used.

B.23 There should be adequate arrangements to ensure a supply of fuel for back-up generators is available with contracts for replenishment.

B.24 The standby power supply should be of sufficient capacity to fully support the operational power load in the period between power failure and the cut over to the alternative supply. Where power is provided by batteries, the battery capacity should be specified to maintain service for an appropriate duration at any stage in the battery design life. The duration and reason for the chosen duration should be documented. All batteries should be maintained to manufacturers' recommendations, taking account of expected lives as well as any recommendation to fully discharge batteries on a regular basis. Standby power systems should be exercised to ensure that they perform satisfactorily under failure conditions.

B.25 Where ventilation or air conditioning is used, single failure should not hazard the facility.

B.26 Essential cooling for facilities should be appropriately secured against failure.

B.27 Buildings should be secure against entry by unauthorised people. An adequate level of building security shall be demonstrable and commensurate with to the assessment of levels of risk and vulnerability. Secure entry systems, movement detectors and video surveillance may be necessary, and both perimeter and cellular security may be appropriate in large buildings.

B.28 Equipment should be carefully sited within buildings to provide physical separation and protection where required.

B.29 Processes should be in place to reduce the risk of equipment failure due to building and civil engineering works. Network operators should make information available on planning consents and cable routeing (where necessary providing a helpline to deal with inquiries). Network operators should keep themselves informed about activities of other parties which may present a risk to network security.

B.30 Force majeure:

Network Security

B.31 Network security should be delivered through an appropriate combination of resilience, redundancy, restoration and repair.

B.32 In particular, Oftel expects network operators to:

Network Management and Operational Procedures

B.33 Network management systems allow the remote control and surveillance of communications networks. Network management plays a vital role in both network security and integrity by providing data on events and alarms in the network, allowing the network operator to take corrective actions as required. The appropriate use of statistical data collection is an essential part of network management. Properly designed network management and procedures should mitigate losses due to internal and external events.

B.34 Oftel expects to see effective network management and procedures in place, covering at least the following areas:

B.35 Oftel further considers that for fault management to be effective, there must be evidence of systems and processes being in place for fault detection, fault monitoring, finding the cause of faults, bypassing faults to maintain network performance and fault fixing. Oftel further considers that:

B.36 Oftel considers that the network operator should provide reasonable notice to the affected parties of any planned work (including maintenance) that carries significant risk of impairment to essential service.

B.37 In the case of interconnected network operators, Oftel expects that:

B.38 Oftel considers that good configuration management entails keeping a reliable inventory of network resources and having documented robust processes for the allocation of resources.

B.39 Oftel considers that effective performance management involves the use of data from the network management system and elsewhere to monitor network performance, to gauge performance against specified standards and to manage call carrying capacity to meet specified grades of service. On this point, reference should be made to other sections in these Guidelines relating to traffic management.

B.40 Oftel considers that effective security management in this context involves systems and processes that control access to both the network itself and the network management system. This includes user authentication, encryption, and password protection processes.

B.41 Oftel considers that good accounting management involves robust systems for processing and storing service and utilisation records, and generating customer billing reports.

B.42 Real time traffic management involves the ability to gather data from various parts of the network to allow judgements to be made concerning real time call routeing options, for example, local, trunk, Intelligent Network (IN ) Platforms or Virtual Private Network (VPN) platforms. This may also include the gathering of data from Signalling links, PSN/Internet gateways and Interconnect with other Licensed Operators.

B.43 A network management centre should not be a potential cause of catastrophic failure of the network. Oftel expects that network operators will consider the desirability of geographically separate network management centres, based on an analysis of costs, benefits and risks.

Testing

B.44 Oftel considers that network operators should be able to demonstrate the existence of procedures for testing of the network, including provocative testing of network components as appropriate. Oftel also recognises that it is impossible to test something as complicated as a modern telecommunications network with complete certainty. Therefore network operators should be able to demonstrate that potential failure scenarios have been envisaged and that contingency plans for service restoration have been prepared, tested and are in place. The objective of the contingency plan should be to maintain the network operator's ability to at least fulfil its statutory obligations for service provision in the event of network failure.

Network Integrity

B.45 Network integrity concerns threats to the normal operation of the network that enter via the network itself, and also those that are introduced from outside sources such as customers or other networks. Network operators should plan accordingly to mitigate these threats Such threats include:

Abnormal electrical conditions

B.46 Oftel expects that operators will consider what protection may be necessary on metallic circuits from accidentally applied voltages, current surges associated with earth potential differences and lightning strikes.

B.47 TE may cause a safety hazard by presenting an excessive voltage to the network. The presentation of high voltage to the network termination is clearly only applicable to fixed networks and should only occur after serious TE failure. The threat this presents to the network should be limited to the local loop, as the network should be self-protecting to prevent more extensive damage and reduce the risk to network maintenance staff.

B.48 Network operators should be aware that TE may under certain circumstances inject incorrect signalling information. Conducted or radiated emissions including those from TE may affect fixed networks. They should penetrate no further than the local loop, albeit possibly affecting adjacent circuits.

Access Network Frequency Plan

B.49 Since the metallic access network was not designed for the transmission of high frequency signals, its use for Digital Subscriber Loop (DSL) technology has the potential to generate unacceptable levels of crosstalk (where the signals on one circuit may cause interference to the signals on one or more adjacent circuits).

B.50 The actions of each individual DSL user may have implications for all other users including those not using DSL services. It is therefore essential that the interference environment within an access network is controlled and managed to prevent accidental or malicious degradation of service and to this end some form of Access Network Frequency Plan (ANFP) is required. An ANFP will essentially specify what signals can be injected into the network and this will have direct implications on the type of technology that can be deployed and consequently the type of services that can be provided. An ANFP is intended to control interference caused by systems that directly transmit into the network and subsequently cross couple. It will have no control over signals that are coupled into the network from external electromagnetic sources.

B.51 Future developments may make it easier for end users to unwittingly inject spurious signals into the network. Oftel expects that network operators will keep themselves informed of any emerging risks in this area, and any other initiatives that may arise from time to time that have the potential to present similar threats to network integrity.

B.52 There are many possible ways of structuring and presenting an ANFP. Oftel does not have a preferred methodology but would point out the advantages of the approach being adopted for BT's network. Different points of connection to the network are defined e.g. exchange end and end-user premises. For each defined point there is an associated power spectral density (PSD) mask. The mask describes the maximum power envelope that can be injected into the network at that point. This approach is technology neutral and transparent, and allows equipment designers to comply with the plan at the design stage.

B.53 Network operators must not compromise the appropriate ANFP.

B.54 Oftel has commissioned the NICC to make appropriate recommendations. Outputs from the DSL task group set up by the NICC to undertake the detailed work are published on Oftel’s web-site (www.oftel.gov.uk/ind_groups/nicc/index.htm).

Inappropriate use of signalling protocols

B.55 Incorrect signals received from outside can interfere with the correct operation of the network. Such signals might be benign in intent and be caused by accidental mis-operation of other equipment. However, they may also be caused by deliberate attempts to interfere with network integrity, for example to avoid the proper charging for network services (phone fraud), to deny service to others, or to corrupt stored data or software. Multiple levels of security may be needed to counter such threats, including signalling ‘policing’, firewalls etc.

B.56 TE may under certain circumstances inject incorrect signalling information. The network should be self-protecting and ignore incorrect signalling from TE which does not conform to the expected protocols. Nonetheless, such signals may interfere with or mask legitimate information. Correctly formatted but erroneous signalling may be more dangerous to the network, for example malfunctioning automatic dialling equipment congesting the network with unwanted calls.

B.57 Oftel expects that network operators will implement the Calling Line Identity (CLI) Code of Practice [B4] to assist, inter alia, with tracing the source of signals.

B.58 Screening (also known as policing) is a technique which can be used at the edge of the network to protect it from mis-operation of connected networks. Candidate areas for screening might be:

B.59 Oftel expects to see appropriate precautions to guard against and respond to hacking and electronic attack. In addition, Oftel encourages network operators to make use of appropriate industry fora to cooperate on these issues.

B.60 The introduction of STPs in the UK network to carry signalling traffic poses a particular risk to network integrity. If networks are interconnected through STPs it is not possible to easily isolate interconnected networks from each other. Problems in one network could spread to other networks via STPs unless careful monitoring is implemented.

B.61 Potential problems associated with STP working include:

Terminal equipment

B.62 Instances have been given above where TE may pose a threat to network integrity.

B.63 Physical disconnection of fixed line TE can protect the integrity of the network from risks posed by TE. The regulatory framework allowing such disconnection is set out in Annex BA.

Excessive traffic loads

B.64 Networks need to be protected from traffic overload conditions. Network Traffic Management (NTM) is a set of tools and techniques for detecting, monitoring and controlling network traffic to protect the network from abnormal loads, while at the same time optimising network performance. While NTM is capable of dealing with mass calling behaviour, Oftel recognises that complete service denial or disconnection may be required to control excessive traffic from (or to) a single subscriber.

B.65 Oftel expects network operators to adhere to the following NTM principles in protection of essential service:

B.66 Network operators should be able to demonstrate the capability for manual or automatic traffic management, with variable degrees of implementation depending on the magnitude of the problem, in the following categories:

B.67 Network operators should have:

B.68 Oftel accepts that in some cases, network operators with small networks consisting of only one or two switches may choose not to invest in NTM facilities but instead rely on controlling their interconnect with other networks that do provide NTM.

B.69 Oftel recognises that congestion can be created in one network, and have an impact on a competitor's network due to network interconnection. If steps are taken in the affected network to reduce the impact of excessive traffic, typically by call-gapping, it is conceivable that another network operator may have cause to complain that its ability to carry revenue-earning traffic is restricted. Conversely if no action is taken the affected network could fail. It is important for network operators to understand that good network traffic management actually maximises the effective (ie revenue-generating) call capacity of the network. Oftel therefore expects that:

c) signalling links will be dimensioned to avoid congestion and will in general have much lower occupancy than traffic links. This is due to the importance of minimising the risk of losing signalling messages and the need to reduce signalling latency. The number of signalling links should be established for normal and failure conditions, and some form of planning tool may be required to determine the signalling relationships supported by a given linkset except in very small networks.

Annex BA – The Existing Regulatory Framework for Terminal Equipment

BA.1 TE is connected to the public network at a Network Terminating Point (NTP). It includes, for example, individual mobile, fixed and cordless telephones, fax machines, modems, answer-phones, private branch exchanges and private systems attached to the public networks.

BA.2 RVTD [B1] Article 13(c) (transposed into SI No.1580/1998 [B2] regulation RVTD9.8 and Licence Condition 20.8) specifically excludes the imposition, by the Licensee, of further restrictions on use of TE on the grounds of interoperability of services. TE interoperability has been excluded from the scope of these Guidelines. However, if a measure were being legitimately adopted against TE to preserve network integrity (rather than on the grounds of end-to-end interoperability) it would come within the scope of these Guidelines.

BA.3 Since 8 April 2000, the placing on the market and putting into service of TE is subject to the Radio Equipment & Telecommunications Terminal Equipment Directive (RTTE-D) [B6] which is transposed into UK law by SI No.730/2000 [B7],). Under the RTTE-D [B6], non-radio TE is subject to compliance with the ‘essential requirements’ of the Directive (the safety objectives of the Low Voltage Directive 73/23 and the protection requirements of the Electro-Magnetic Compatibility Directive 89/336) demonstrated by a manufacturer’s declaration of conformity. Additional ‘essential requirements’ may be imposed by a Commission Decision.

BA.4 The former regime of equipment approvals (Directive 98/13 [B8]) came to an end on 7 April 2000, although equipment approved under that regime was permitted to be placed on the market during a one-year transition period up to 7 April 2001. Individual items of approved equipment placed on the market during the transitional period enjoy an enduring right to be connected and put into service. This also applies to the legacy of approved equipment placed on the market before the transition period. However, all apparatus supplied on or after 8 April 2001 must comply with the applicable ‘Essential Requirements’ and other relevant provisions of the RTTE-D.

BA.5 RTTE-D [B6] Articles 7.4 and 7.5 complement the RVTD [B1] provisions, and allow for disconnection of TE. However, Articles 7.4 and 7.5 only apply in the case of apparatus that has been declared to be compliant with the provisions of the Directive, and that has been put into service for its intended purpose. Disconnection procedures for non-compliant equipment are outside the scope of the Directive and are subject to national procedures.

BA.6 RTTE-D [B6] Article 7.4 provides for a Licensee to be authorised by the authorities to refuse connection of, disconnect, or withdraw from service TE which (even though it has been declared to be compliant with the provisions of the RTTE-D) causes

BA.7 R&TTED [B6] Article 7.5 provides for a Licensee to make emergency disconnection of TE, where this is immediately necessary to protect the network. Having taken such a step, the network operator is required to advise the National Regulatory Authority and provide an alternative solution to the customer without delay or costs.

Annex BB – An Overview of the Telephone Emergency Services (999)

Note: When 999 is referred to in this Annex the comment applies equally to 112.

Note on Annexes BB and BC

Annexes BB and BC relate to compliance with the requirements on operators to provide access to the Emergency Service, and could therefore be considered beyond the strict scope of this document. However, Oftel considers that it is beneficial to publish the information in Annexes BB and BC more widely, and the Guidelines appear to Oftel to be a suitable vehicle for doing this.

Oftel would also point out that both Licence Condition 20.3 and Licence Condition 20.4 require Licensees to have ‘particular regard to the needs of Emergency Organisations’ in meeting their network security and integrity obligations. Some parts of Annex BB and Annex BC should be considered as part of the draft Guidelines, in so far as they describe how Oftel would expect the Licensee to meet this ‘particular regard’ requirement.

Therefore, whilst most of the text in Annex BB is included in this document for the purposes of information only, paragraphs BB6, BB10, BB11, BB19, BB20 and BB22 from Annex BB and Annex BC should be considered part of this guidance.

Purpose of this Annex

BB.1 This Annex aims to give, for the avoidance of doubt, an overview of the 999 emergency service and its method of operation as it applies to fixed PTO networks. It also discusses the factors that influence its efficient implementation and introduces the wider issues regarding 999. Oftel is aware that this information, although widely understood and acknowledged, has yet to be formally recorded. Oftel therefore considers it advantageous to include it as an Annex to these Guidelines.

Introduction

BB.2 The provision of access to emergency services is a requirement imposed upon all public telecommunications operators in the UK that provide Publicly Available Telephone Services. In three cases, BT, CWC and Kingston Communications, the Emergency Operator (answering) service is also provided. Oftel issued a statement [B9] following a consultation that confirmed that these three public telecommunications operators would be the only ones that would provide this Emergency Operator service in the interests of maintaining a high quality service. The other public telecommunications operators each make use of one or more of these three answering services. It is a requirement that the 999/112 service provision is provided at no cost to the user. This requirement is specified in the RVTD [B1], Article 9(c).

BB.3 Oftel has a duty to ensure that the public telecommunications operators provide an acceptable quality of service under the RVTD [B1] and 999 service provision is particularly important in this regard.

BB.4 The traditional telephone number in the UK for access to the emergency services is 999, which has been in use since 1937. The emergency services which can be contacted via this number are: Police; Fire; Ambulance; Coastguard; Mountain Rescue; and Cave Rescue.

The relationship between 999 & 112

BB.5 It has been realised that it is desirable for a common code for emergency services across the whole of the EU. Consequently, an EU Decision [B10] required the adoption of the standard emergency access code, 112, within a specified timetable.

BB.6 Further, in recognition of their traditional use, the Decision allowed member states to retain any existing codes. 999 is very familiar to people in the UK and hence withdrawal of this number and substitution by another would inevitably lead to confusion and probable risk. Because of this, in the UK both 999 and 112 provide emergency access in parallel. 999 and 112 must be given equal priority within the whole of the UK public telephone network and this in turn will be a higher priority than other traffic.

Note: The introduction of 112 to the UK telephone network did cause some problems that resulted from fault conditions and misuse of customer premises equipment. In particular, spurious ‘1s’ and ‘2s’ could be caused by line faults, or by repeated tapping of switch-hooks on lines with loop-disconnect signalling, causing false calls to the Emergency Operator. The term ‘Emergency Operator is used to describe the assistance operator assigned to the processing of 999 calls to the emergency services. Measures were introduced within the signalling system to reduce the number of these false calls reaching the Emergency Operator. This raises two issues:

a) additional (false) calls could increase the load on the Emergency Operator (the net increase in traffic handled by the public network being relatively insignificant); and

b) methods used to reduce false calls could reject legitimate calls. It remains the case that public telecommunications operators should ensure that false calls are reduced to a minimum and are not introduced by equipment malfunction.

Description of the Emergency (999) Service

BB.7 In order to appreciate fully the requirements for an effective Emergency Service it is essential that the components that make up an emergency call are understood. There are three basic stages in the set-up of an emergency call:

BB.8 Call set-up is illustrated in the diagram below:

Any of these stages can be further complicated by the originating/destination public telecommunications operator being different from that answering/handing off the call. This could result in as many as three public telecommunications operators handling the call.

BB.9 The initial set-up of the call from customer to Emergency Operator may take a number of routes:

a) originating from a fixed or mobile network; and

b) possibly transitting across a point of interconnect.

BB.10 In each case, it is essential that the emergency call be given higher priority than other traffic. For the first stage, this is easily achieved based upon the dialled number, using various techniques to give additional routeing diversity and priority over globally set network management regimes.

BB.11 Having arrived at the operator assistance ACD (Automatic Call Distributor) the call is placed in a queue. This will either be a separate high priority queue or a common queue, if the latter the call will be given some priority, for example by giving the emergency call an artificial time advantage by it appearing to have been in the queue for 10 minutes as soon as it arrives.

BB.12 So far as availability of Emergency Operators is concerned, it should be noted that the Emergency Operator is not normally assigned exclusively to one type of call but will potentially answer both assistance and emergency calls.

BB.13 For fixed networks, the Network CLI must be passed to the Emergency Operator. If the CLI is not forwarded it will not be possible, efficiently, to forward location information to the Emergency Organisations. (Note that this Annex does not refer to what may or may not happen in the case of calls to the Emergency Operator originating on a mobile network).

BB.14 For fixed networks, the CLI is displayed to the Emergency Operator (note: the use of 141 as a call prefix will not prevent the customer’s number being displayed in this case). The CLI performs a number of functions:

BB.15 For fixed networks, the Emergency Operator then passes the call to the correct Emergency Organisation. The installation address, customer name and telephone number is passed, either as a voice message or as data.

BB.16 It follows from the above that there must be a database that holds customer information related to the CLI. Further, it also follows that this database will have to be populated with data not only from the host company (the PTO providing the operator services) but also those PTOs subscribing to the service (this will include certain LLU operators). The data required for each customer is as follows:

• customer name;
• customer address, including postcode;
• customer telephone number;
• PTO name; and
• an indication if the customer is ex-directory.

BB.17 The database is updated regularly, several times each day from data provided by the PTOs. This emergency database is only accessible by the Emergency Operator, and is not available for commercial purposes.

BB.18 For the second stage, priority is established by means of the signalling protocol. Whilst the second stage of the call is being established, and if required during the period that the Emergency Operator has established a connection with the caller, the Emergency Operator can both monitor and ‘backward-hold’ the call.

BB.19 It is also essential that maintenance of exchange lines over which calls are passed to the Emergency Organisations is given a high priority.

BB.20 The essential protecting of the network is vital – if the entire network, or a significant part of it, is not functioning it does not matter how much priority is given to 999 calls, they may still not mature. Matters of network integrity and security are dealt with in the main body of these Guidelines, although clearly operators should give special consideration to the needs of the telephone emergency service.

BB.21 Access to the emergency service is provided for the hearing impaired via Textphone. The current number used (as at the date of publication of these Guidelines) is 0800 112999, this service will shortly also be provided via the 18000 access number.

Annex BC – Requirements for ‘Lifeline’ Telephony

Note on Annex BC

Attention is drawn to the Note at the commencement of Annex BB which explains the applicability of Annex BC and how it should be considered part of this guidance.

In the clauses of this Annex, the text preceded by the word ‘NOTE’ should be considered solely as informative.

BC.1 All operators providing Publicly Available Telephone Service (PATS) must meet all the relevant obligations in the RVTD [B1].

NOTE: PATS is not defined in the RVTD and therefore Oftel has provided the clarification that it should be taken to mean a telephone service which is made generally available and would in principle be provided to anyone prepared to pay for it, capable of using it (in the case of wholesale products) and to abide by the applicable terms and conditions. The general availability of PATS is in contrast to a bespoke product which is offered only to one or a limited class of customers.

BC.2 All providers of PATS must provide robust and resilient access to the 999/112 service. Routeings must provide a very good grade of service, avoiding single points of failure as far as reasonably possible and supported as appropriate by such techniques as automatic alternative routeing, repeat attempts, priority call attempts, and trunk reservation. The speech connection must be of a quality to allow two-way, simultaneous, uninterrupted and readily intelligible conversation with 999/112 operators and the emergency authorities. It must also allow the transport of Textphone low speed in-band data signals. If ‘Voice over DSL’ or ‘Voice over IP’ is used, the operator must maintain complete control over the packet contention to ensure this quality.

NOTE: Oftel takes a technologically neutral approach to regulating voice telephony. A service is deemed to be PATS if it is either sold as a substitute for traditional public telephony service, or appears to the end user to be so, or if it provides the sole means of customer access to the traditional PSTN. Thus ‘Voice over IP’ and ‘Voice over DSL’ would be considered to be PATS if they meet this definition and therefore the RVTD obligations would apply.

BC.3 Calling Line Identity (Network CLI) must be forwarded to the 999 operator to assist the handling of emergency calls. The Network CLI must normally unambiguously identify the calling customer, in order further to identify the address of the caller.

NOTE: There are a few cases where the CLI may not immediately identify the location of the caller, eg remote extensions on private networks or when calls are placed by an intermediary eg Social Alarm providers. Operators should ensure that callers are aware of such cases so that the 999 operator can be advised where the received CLI is not valid, but such arrangements should be considered as exceptional and should not be depended on for general use, since tracing ‘silent 999’ calls depends entirely on the provision of a valid CLI.

BC.4 Access must also be provided to the 100 Operator Service and nationally important ‘safety of life’ help-lines in the 0800, 0808 and 0845 number ranges. NOTE: The following services are recognized by Oftel as being ‘safety of life’ services of national significance:-