1 DOCUMENT FOR: GSC-8/GTSC-1/GRSC-1 Ottawa, Canada 28 April – 1 May 2003 GSC-8-021

2 Broadband Access: Cutting through the standards maze Presented by Keith G Knightson 1Decision or Action Requested Promote development of rationalization among Broadband Access standards, and open access model. 2References 3Issues for Discussion Proposals for rationalization and open access.

3 Abstract: This contribution will outline the diversity and complexity of standards associated with the provision of Broadband Access, using DSL, Cable and Fixed Wireless systems. Recommendations will be made for the reduction and rationalization of standards among these systems, together with the potential use of layer 2 standards for facilitating access to Internet Service Providers.

4 Standards Issues Standards Challenges: Multitude of different protocol stack combinations; Provision of standardized points of interconnection for open access.

5 Cable Systems Protocol Standards Physical Media Transmission Convergence (downstream only) MAC Link security Ethernet IP & ICMP ARP SNMPTFTPDHCP Security Management UDP IP over Ethernet

6 DSL Systems Protocol Standards PPPoA PPP DSL ATM AAL5 LLC or VC Mux Ethernet PPPoE PPP L2TP PPP IP PPPoAIP/EthPPPoE IP/AAL5 L2TPoA

7 Fixed Wireless Broadband Protocol Standards Physical Layer Transmission Convergence Privacy MAC IP Convergence ATM Convergence Ethernet Convergence

8 The Maze Some stacks use Ethernet, some don't, Some stacks use ATM, some don't, Some stacks use PPP, some don't. Lack of open Point of Interconnections (POIs) at each layer, results in bundling of service with transmission. LAN access problems: Different LAN Users access to different ISPs. ISPs access to specific LAN users.

9 Guidelines for Interconnection Standards Principle 1 The variation between protocol stacks should be reduced to a minimum. Principle 2 The commonality between protocol stacks should be maximised. Principle 3 Tunneling should be used “interwork” non-compatible network segments. Principle 4 The protocol stack should be consistent with independent provision of any of peering points at any layer in the protocol stack.

10 Guidelines for Interconnection Standards (2) Principle 5 The protocol stack should facilitate the provision of value-added services. Principle 6 The protocol stack should facilitate access security. Principle 7 The protocol stack should facilitate QoS provision (involving quantifiable and measurable levels of service). Principle 8 The protocol stack should provide flexibility for mixing and matching different underlying physical media. Principle 9 There should be equal access to the point of community aggregation.

11 Scope for Protocol Stack Rationalization? IP PPP AAL5 Ethernet L2TP Various Physical Media Simplification and Facilitation of ISP interconnection Recommendation:

12 Recommended Interconnection/Peering Arrangements ISPs Metro Ethernet Local Ethernet DSLAMDSLAM ISPs L2TP/PPP ISP Metro ATM Last mileMiddle mile Users Ethernet Switch AAL5 Stack Ethernet Stack AAL5 Stack = Potential layer 2 POIs CATV LMDS

13 User1 SP1 SP2 SP3 SP4SP5 User2 Access or Backbone Broadband: Equal Access Model SP = Service Provider

14 SP7 SP3 SP4 SP5 SP6 User1 SP1 User2User3 User4 SP2 User5User6 Backbone Access Broadband: Bottleneck Access Model

15 The separation of service from facilities, Access should permit: independent provision of terminal equipment, user choice for service provision, and use of multiple service providers. Policy recognition of two access frameworks: Equal Service Access Architecture, and Bottlenecked Service Access Architecture. Mass migration from dial-up access can be expected. Broadband Access Issues - 1

16 Standards need to be rationalized among access systems such as DSL, cable wireless, etc. User lock-in is a common issue, due to proprietary and bundled systems. No technical reason why all services (voice, data, video) cannot be supplied over a single physical medium, i.e. integrated services access. Policy may be key to deployment of integrated services access and choice/competition. Broadband Access Issues - 2

17 Need for: Rationalization of protocol stacks for Broadband Access. Recognition of unbundled access model(s). Conclusions

18 Broadband Access: Cutting through the standards maze KGK Enterprises 1806 Lahey Court Kanata Ontario, K2W 1B2 Tel:

19 Peering/Interconnection Models (1) User NodeNetwork Node Continuous physical medium End-to-End continuity Physical Layer Data Link Layer Network Layer Physical Layer Relay Physical Layer Data Link Layer Network Layer User NodeNetwork Node Physical Layer Data Link Layer Network Layer Physical Layer Data Link Layer Network Layer Discontinuous physical media

20 Peering/Interconnection Models (2) Physical Layer User NodeNetwork Node Physical Layer Data Link Layer Network Layer Physical Layer Data Link Layer Network Layer Data Link Layer Relay Discontinuous physical media Discontinuous Data Link Physical Layer User NodeNetwork Node Physical Layer Data Link Layer Network Layer Physical Layer Data Link Layer Network Layer Discontinuous physical media Data Link Layer Discontinuous Data Link Network Layer Relay Discontinuous Network Layer