Tuesday, December 22, 2009

NBN Broadband Plan

NBN Co diagram of Fibre Serving Area, Indicative Access InfrastructureNBN Co have issued "NBN Co consultation paper: proposed wholesale fibre bitstream products" (21 December 2009) . Written submissions are invited by 12 February 2010 and Industry Briefing Sessions will be held in Sydney and Melbourne, on 20 and 29 January 2010. \

The paper is 27 pages (2.6Mbytes of PDF). It is very precisely, but clearly written. There are well executed technical diagrams. Of particular note is the diagram for "Fibre Serving Area – Indicative Access Infrastructure" illustrating the relationship between Multi Dwelling Units, Internal Fibre and Optical Network Termination. The only suggestion for improvement I could make is for NBN Co to produce a web version.

Of note:
  1. NBN Co plans to provide Ethernet: "It is NBN Co’s view that the Layer 2 products for mass-market fibre services should be based on Ethernet delivery, utilising GPON as the physical access technology. Please note that NBN Co has yet to define Layer 2 offers beyond the mass-market."
  2. NBN Plans support for voice, video and other QoS sensitive applications, with 4 classes of service.
  3. A Plain Old Telephone Service (POTS) is being considered with an Analogue Telephone Adapter (ATA) integrated within the Optical Network Termination (ONT).
  4. In its consultation process NBN Co. specifically mentions the Communications Alliance: "... NBN Co will continue to collaborate with industry as part of the Communications Alliance process."
  5. NBN Co intends to support multi-cast protocols, which allows for broadcast like services for IPTV and digital radio: "As NBN Co intends to deliver a multi-cast capability, some Layer 3 awareness will be required within the NBN to support the delivery of IPTV services."
Some excerpts from the paper:
  1. Introduction 3
  2. Building a fibre access network 6
  3. NBN Co’s overall product objectives 8
  4. Choice of layer in the vertical technology stack 9
  5. High level technology standards 12
  6. Location of Points of Interconnect for NBN Co wholesale fibre network 14
  7. NBN Co wholesale fibre bitstream products definition 17
  8. Important product elements 20
  9. Conclusion and next steps 24
1. Introduction Background
NBN Co’s role is to realise the Australian Government’s vision for the development of a next generation national broadband network. To do this successfully, we need to consult widely to ensure our plans for the network meet the current and future needs of our wholesale customers and the wider Australian community.

This Consultation Paper:
  • sets out the conceptual framework that will underpin the development of our proposed wholesale fibre bitstream products
  • focuses on the 90% of premises that are expected to receive high speed broadband services through fibre to the premises (FTTP) technology.1 It does not consider wholesale product offerings over wireless or satellite networks
  • outlines our current thinking on the design of the NBN Co fibre network and the wholesale bitstream products to be provided over that network
In particular, this paper will discuss:
  • the objectives that will underpin NBN Co’s development of its fibre wholesale products
  • the level in the vertical technology stack in which NBN Co intends to offer its fibre wholesale products
  • the high-level technology standards on which NBN Co will build its network
  • NBN Co’s proposed policy for determining the location of Points of Interconnect (PoIs)
  • an overview of the two fibre wholesale products that NBN Co intends to initially offer to its wholesale customers
  • the service features that are intended to be supported by NBN Co’s wholesale fibre products
This Consultation Paper does not attempt to outline the full details of NBN Co’s proposed wholesale fibre products, nor does it describe the various pricing structures of those products. The price structure of our wholesale fibre products will be presented to the industry during NBN Co’s consultation program that will take place in early 2010.

1 Note that in some deployment scenarios (e.g. Multi-Dwelling Units or MDUs) fibre will be delivered to the premises and distribution of services to individual units or service locations will occur via internal building wiring. The details of the MDU solution are not contained in this Product Consultation Paper.

Summary of NBN Co’s proposed wholesale fibre products
  • NBN Co plans to offer a wholesale Layer 2 bitstream product – in doing so, NBN Co will seek to occupy as small a footprint as possible in the overall value chain, leaving retail service providers (RSPs) with significant ability to innovate and develop new services in the higher levels of the value chain.
  • The location of PoIs will be optimised to support healthy competition among RSPs and align with contestable backhaul. For more densely populated areas, such as urban and regional centres, a “local” Point of Interconnection (PoI) is will be established for each Fibre Serving Area (FSA),2 while for less densely populated areas, a “district” PoI (which aggregates two or more FSAs together), will be established. If competitive backhaul is not available from a PoI, supplementary provision of backhaul may be required for a limited period of time to permit the emergence of competitive backhaul on these routes. Only one PoI will be available for any FSA. The number and location of PoIs is still to be determined.
NBN Co will offer its wholesale Layer 2 bitstream product in two forms:
  • the ––Local Ethernet Bitstream (LEB) product will provide our wholesale customers with a Layer-2 access service between the Optical Network Termination (ONT) at an end-user premises and a “local” PoI, located at the Fibre Access Node for the relevant FSA. The LEB product is likely to be offered in capital cities and regional centres. It is envisaged that the LEB product will be made available in respect of the significant proportion of FSAs in Australia.
  • the–– Aggregated Ethernet Bitstream (AEB) product is likely to be offered in rural areas where there are no competitive backhaul services below the PoI. The AEB product enables aggregated access to one or more FSAs via an aggregated link. The LEB product will not be available in locations where the AEB product is made available.
Both the LEB and AEB products offers will be based on an Ethernet platform, utilising Gigabit Passive Optical Network (GPON) as the physical access technology. The technology will deliver a range of active service features including security and Quality of Service (QoS), as well as IP multicast.

Our wholesale products will support access by multiple RSPs, a range of customer premises • equipment (CPE) and will include an interface for analogue telephony. The detail of how these elements will be presented to our wholesale customers will be discussed in later consultation papers.

2 A Fibre Serving Area (FSA) is defined as the area covered by one or more Passive Optical Networks (PONs) terminating at the same “Fibre Access Node”.


2. Building a fibre access network

90 per cent of Australian premises are planned to be served by a fibre access network. While NBN Co is currently undertaking a detailed assessment, planning and design process, to facilitate the consultation program, an indicative configuration of the access network is set out in the
following diagram:

NBN Co diagram of Fibre Serving Area, Indicative Access Infrastructure


4. Choice of layer in the vertical technology stack

... NBN Co considers that a Layer 2 product is most closely aligned with NBN Co’s stated objectives and is most likely to facilitate the achievement of optimum competitive outcomes over the short-to-medium term. Layer 2 products are also most likely to support end-user choice and simplicity, while avoiding the downside risks associated with Layer 3 products, such as a lack of competitive differentiation and limited scope for innovation. ...

5. H High level technology standards

It is NBN Co’s view that the Layer 2 products for mass-market fibre services should be based on Ethernet delivery, utilising GPON as the physical access technology. Please note that NBN Co has yet to define Layer 2 offers beyond the mass-market. ...

Point to multipoint technologies (known as PON – passive optical networks) such as Ethernet Passive Optical Network (EPON) and Gigabit Passive Optical Network (GPON) provide a shared medium for customers, with only individual fibre tails post the splitter. In contrast, point-to-point optical networks provide customers with a full fibre for their exclusive use. ...

Do you believe this model will help foster participation by RSPs in less densely populated locations? What other barriers exist to participation by RSP in these locations? How might NBN Co help address them? Do you believe this model allow sufficient space for participation and investment by commercial backhaul players? What concerns may need to be managed? What criteria should be considered when determining whether the currently available backhaul to a particular proposed regional or district PoI is competitive? What criteria should be considered to assess the likelihood of competitive backhaul being developed in the near-term future at a regional or district location where present backhaul options are not yet deemed to be competitive?

7. NBN Co wholesale fibre bitstream products definition

A. The product offering
NBN Co is proposing to initially offer the following two FTTP products to the market:
1. Local Ethernet Bitstream (LEB)
2. Aggregated Ethernet Bitstream (AEB)
Essentially, both products have the same access capability, with the AEB service offering a short-haul aggregation service for those rural and regional areas where contestable backhaul options have not yet emerged. ...

8. I Important product elements

Traffic Management & Prioritisation

NBN Co’s product offering will provide QoS options to support voice, video and other QoS sensitive applications (although timing of these options is subject to current assessment). Ethernet and GPON provide the capabilities to support a QoS differentiated product. The LEB and AEB products will support 802.1p identification of Ethernet traffic priority. ...

At this stage NBN Co is planning to support 4 classes of service although it has not been determined when and how all options would become available. They are:

  • Provides guaranteed low levels of delay and jitter
  • Suitable for voice and other communicative services. This is the highest priority traffic
  • Assurances for the levels of jitter and packet loss
  • Suitable for video / VOD, including multicast services
  • This class provides a second highest priority of traffic
  • Provides a higher level of assurance than the best effort class, with lower probability of delay, jitter and congestion
  • Suitable for commercial data services, business grade data services
Best effort
  • No performance guarantees
  • Suitable for high speed internet
  • This is the lowest priority traffic and anticipated to carry high volumes of data with varying levels of performance according to instantaneous congestion

Voice Option

As a means to aid transition from current access technologies to the NBN, inclusion of Plain Old Telephone Service (POTS) capability is being considered to support legacy telephony services.

It is proposed that this will be achieved via an Analogue Telephone Adapter (ATA) integrated within the Optical Network Termination (ONT). Session Initiation Protocol (SIP) will form the core of the interface definition for this capability. Further details of the implementation of the POTS capability will be released in due course. ...


Multicast is a technology whereby content transmitted simultaneously to two or more end users (e.g. IPTV programs) is carried as a single stream as far into the network as possible before being replicated (i.e. divided) and on-forwarded to end-users. Replication may occur at more than one point along the end to end path, resulting in a tree of replicated streams. The multicast technique can achieve significant bandwidth savings for the delivery of one-to-many services.

It is NBN Co’s intention to deliver a multicast capability, which will require the incorporation of some Layer 3 awareness to support its delivery. The details of multicast implementation are still under consideration. ...

This section outlines key elements of NBN Co’s planned product specification. Are there any other • technical parameters that should be included?
What multicast capabilities have service providers identified? Should the NBN Co access network proxy IGMP functionality and consolidate reporting before passing messages through to the service provider, or do particular services require access to all IGMP communications from all end users? In other words, should NBN Co manage multicast signalling scalability on behalf of the access seekers, or would this unacceptably limit the kinds of multicast services that are being contemplated? How to provide SPs with the ability to confirm connectivity and power? Whether standards are required for CPE installation, reporting and management to allow customer • self install, remote CPE configuration and downstream service provisioning? How to ensure continued support for smart grid and other public services such as safety, health and education? How should legacy voice services be provided? The benefits and disadvantages of integrating Pay TV capabilities into the ONT? The merits and disadvantages of an RF Overlay approach towards Pay TV versus an IP multicast approach?
Should battery backup capabilities, for the purpose of maintaining POTS (or optionally, data) • connectivity for a limited period of time following a power outage, be offered to end users at the time of ONT installation and should the choice be optional? How can the environmental costs be responsibly managed and how can the costs appropriately shared between end users and their chosen RSPs? How can end users be best educated to make an informed choice? ...

From: NBN Co consultation paper: proposed wholesale fibre bitstream products, NBN Co, 21 December 2009

1 comment:

Dmitri Kalintsev said...

Actually, the FSA diagram is somewhat confusing, with black line (DF) and red line (LF) simply joining underneath (?) the top-left FDH; plus bottom right FDH has a segment of red line (LF) going nowhere.

I would have expected more rigor in preparing such a widely distributed document.


-- Dmitri