Ethernet Active Line Access: Updated Technical Requirements

Discussion Document: To accompany the policy statement document: Delivering super-fast broadband in the UK

Executive Summary

Why Ethernet Active Line Access

1.1 Super-fast broadband is expected to deliver real social and economic benefits for consumers, as described in the accompanying policy statement, ‘Delivering super-fast broadband in the UK’[ ^(-1-)]. This document puts forward the updated technical requirements to enable standardised, competitive wholesale active access to super-fast broadband networks; a wholesale bitstream access which, unlike previous forms of bitstream, offers Communications Providers (CPs) scope for innovation and retail product differentiation which is as close as possible to that allowable by passive infrastructure access. We call this type of fit for purpose bitstream access Ethernet Active Line Access (Ethernet ALA).

1.2 The Ethernet ALA technical requirements are targeted at standardisation bodies, infrastructure providers, wholesale providers, potential purchasers of ALA products (ALA-users[ ^(-2-)]), regulators and other stakeholders in next generation broadband development. The document is designed to provide guidance for industry, and the requirements should not be interpreted as a regulatory remedy or a legally enforceable obligation at this time.

1.3 The delivery of super-fast broadband services is generally realised by the deployment of fibre deeper into the network architecture, replacing some or all of the existing, traditional copper access network. Competitive provision of services is necessary to ensure consumers reap all the benefits of super-fast broadband. The evolution of network architecture means that existing options for competitive access may no longer be technically or economically feasible. Regulators therefore need to consider the options for providing competitive wholesale access. T he diagram below positions different access methods in terms of the scope for innovation they allow:

Figure 1 : Examples of active and passive access methods being considered by Ofcom

1.4 Regulators usually favour passive access as it provides CPs with the greatest level of control over the underlying infrastructure. This, in turn, provides the greatest scope for innovation, allowing CPs to reduce costs and prices, and develop new products, bringing real benefits to consumers. Passive access methods such as sub-loop unbundling and duct sharing are under detailed consideration by Ofcom and other regulators. In practice, the exact scope for passive based competition is likely to depend on local characteristics such as population density, network architecture and technology and the state of market development. Our analysis so far suggests that passive-based delivery of super-fast broadband is likely to be considerably more expensive than for the current generation of broadband services[ ^(-3-)]. Given this, active access methods are likely to have a more important and sustained place in super fast broadband competition. Additionally, there are a range of infrastructure options for super-fast broadband (e.g. FTTH, FTTC), and the choice is likely to depend on local conditions. There is therefore likely to be a patchwork of NGA networks based on different technologies and, in the absence of ALA, this would limit economies of scale, discouraging service providers from providing services to smaller markets

1.5 This high level analysis suggests that for ALA to be effective, it needs to support four overarching principles to enable competition.

1.5.1 ALA should provide the maximum opportunity to innovate (i.e. be implemented at lowest possible OSI[ ^(-4-)] layer);

1.5.2 ALA should be standardised to avoid geographic segmentation in service offerings; and

1.5.3 The development of ALA should aim to minimise additional cost and complexity for both service providers and network operators.

1.5.4 The core functionality of ALA should be appropriate to the delivery of residential services. This should not preclude additional functionality being added to deliver business services.

Role of the regulator

1.6 In general it is Ofcom’s view that technology choices are best left to the market, and we have to be technology neutral. In a competitive market, CPs and their suppliers will generally have the right incentives to standardise technologies where they need to. However, Ofcom was concerned that in this case industry might deliver standards too late, once competition has been foreclosed, or standards would be too heavily influenced by the desires of vertically integrated operators to limit downstream competition. These concerns were also raised by industry stakeholders in our consultation on New Build[ ^(-5-)]. We therefore foresaw an important role in facilitating early discussion and agreement between stakeholders on the competitive characteristics and technical requirements of Ethernet ALA. Starting in 2007, we have held seminars with industry stakeholders including infrastructure providers, end users, communications providers and vendors in the UK and abroad. As part of this, five key characteristics were agreed, which are set out below. These characteristics were then further refined with industry into the draft set of technical requirements, published in September 2008 with the aim of facilitating definition of standards by industry. The full process, with the remit of each stakeholder, is shown in the figure overleaf.

Figure 2 : Development of Ethernet ALA with remit of stakeholders

1.7 The draft requirements published in September have now been updated following formal responses[ ^(-6-)], industry seminars and informal engagement. Ofcom intends to pass these requirements over to industry, in order for it to provide a common reference around which stakeholders can engage. It should be noted that the requirements are for technical functionality, not a specific wholesale product (or products). Ofcom expects that, once agreed within industry, the requirements could be met by multiple products that would be chosen according to the specific physical and economic conditions in each implementation. It should also be noted that the requirements are for core, minimum functionality, and should not be read to preclude any additional functionality, except where the addition would contradict an existing requirement.

Choice of Ethernet

1.8 At the beginning of the process it made sense to recommend an interface technology to facilitate the development of ALA. There are a number of technical issues associated with ALA that would be difficult to address on a generic basis. The interface technology needs to be infrastructure independent, well established and have the scope to deliver innovative services. Ethernet has proven to be simple, low cost, ubiquitous and well developed. There is a wide availability of low cost equipment and it is well standardised. It supports flexible bandwidth, excellent interoperability, and security and Quality of Service (QoS) protocols. It operates at a low OSI layer (“Layer 2”) allowing innovation in services and the standard is being adopted by telecommunications companies around the world for transport of IP based services. Also, carrier grade Ethernet has received significant investment and standardisation over the past few years, and many of these advances can be leveraged for ALA. In consultation with industry[ ^(-7-)], the use of Ethernet for ALA has been an uncontroversial choice.

The key characteristics

1.9 The characteristics identified with industry giving ALA-users a level of control and scope for innovation that is as close to passive access as possible are:

1.9.1 Security enablement : Secure delivery of services is essential in today’s market; ALA should separate different traffic streams and allow ALA-users to implement their own security measures;

1.9.2 Quality of service (QoS) enablement : QoS is an important part of competitive differentiation; therefore ALA should support QoS according to current industry standards. In the case where multiple ALA-users supply an end-user , the end-user should be able to decide how their services are prioritised;

1.9.3 Multicast support : Economic distribution of liner audio visual content requires multicast functionality, therefore it should be part of the standard, with the option for either the ALA-provider or the ALA user to implement it;

1.9.4 Flexible customer premises equipment (CPE) : CPE is a key part of the end-user experience; therefore there should be support for flexible CPE; and

1.9.5 Flexible interconnection : As there is no one economic interconnection point, ALA interconnection should be flexible and should be available at a national, regional and local level. At the national and regional levels it is expected to be an aggregated interface.

1.10 Ofcom considers the additional operational requirements for delivering an ALA service to be critically important, and that current industry practices can be leveraged to create the ‘service wrapper’ for ALA. The systems and business process for Ethernet ALA should be as close as possible to those currently employed, and the relative benefits of a common ordering approach should be investigated. Migrations should be as straightforward as possible, i.e. for end-user s, both onto the new technology and between ALA-users, and also for ALA-users between interconnection points. Finally, service and network management and its associated protocols, such as Ethernet OAM, should also be explicitly explored by standards bodies. While the operational requirements are not the focus of this document, we encourage industry to engage in these issues and find workable solutions.

1.11 The key characteristics, and the operational requirements, are summarised in the conceptual representation of ALA functionality overleaf:

Figure 3 : Conceptual summary of ALA functionality

Next steps

1.12 We hope that the requirements set out in this document will provide a framework to facilitate the development of standards for competitive active line access, and would encourage all industry stakeholders to engage in the standardisation process. We further hope that once developed, Ethernet Active Line Access will support a diverse and competitive NGA market with benefits for all consumers. Our next steps will involve handing these requirements over to standards bodies such as the Broadband Forum, MEF and NICC. Following handover, Ofcom will continue to promote the standardisation of ALA across Europe, while monitoring the development of ALA-compliant standards and associated products.

Footnotes:

1.-http://stakeholders.ofcom.org.uk/consultations/nga_future_broadband/statement/

2.- ‘ALA-users’ are those communications providers that would purchase wholesale ALA-based products.

3.-http://stakeholders.ofcom.org.uk/consultations/nga_future_broadband/statement/

4.- Terminology associated with the layers of the OSI protocol stack is used throughout this document. The focus is on the lower 3 layers of the stack: physical, data-link and network. Further detail on the functionality of the stack can be found in Annex ‎3.

5.-http://stakeholders.ofcom.org.uk/consultations/newbuild/statement/

6.-http://www.ofcom.org.uk/telecoms/discussnga/eala/responses/

7.-http://www.ofcom.org.uk/telecoms/discussnga/eala/ethernetala/

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