1. AT&T AMT Multicast Trials Patricia McCrink pmccrink@att.com 11/09/2009

2. Outline Page 2 AT&T Trial Activity – AMT Multicast Motivation Overview of Trial Technical Learnings Opportunities for Further Discussion Improved standardization & development

3. AT&T AMT Multicast – Motivation Multicast will play a critical role in cost-effective delivery of content for both network and content providers However, the Internet is not currently universally multicast capable – especially broadband access networks and home network equipment such as RGs (Residential Gateways) As an interim solution, use AMT (Automatic IP Multicast without Explicit Tunnels) (1) to tunnel through non-multicast- capable networks (1) IETF Draft “draft-ietf-mboned-auto-multicast-09”, June 27, 2008 Page 3

4. Automatic Multicast Tunneling PC ATM Broadband Access POPs Aggregation Subscriber Premises Core POPs Typical Current Network Access Router Core Router Hub Router BRAS DSLAM RG HR CE Native-Multicast End-to-End PC Ethernet Broadband Access POPs Aggregation Subscriber Premises Core POPs Multicast Network - Target Access Router Core Router Hub Router BRAS DSLAM RG HR CE Native-Multicast BackboneTunneled-Multicast Access Multicast Network with AMT ATM Broadband Access POPs Aggregation Subscriber Premises Core POPs Access Router Core Router Hub Router BRAS DSLAM RG HR CE AMT Relay PC AMT Client Multicast capable and ready Multicast incapable Page 4

5. AT&T AMT Multicast Trials Overview Use PIM-SSM (Protocol Independent Multicast – Source Specific Multicast) over AT&T multicast-capable CBB (Core Backbone) network AT&T-developed AMT Relay and GW (Gateway) End-to-end Service delivery perspective Integrated with AT&T CDN (Content Delivery Network) Content-request handling/routing logic Coexistent with unicast Service Logic interacting with PC Client Seamless failover Service Assurance Accounting/Reporting AAA (future) Page 5

6. AT&T AMT Multicast Trial Architecture Content Ingest AT&T Multicast Enabled Network AT&T Multicast Enabled Network Non Multicast Enabled Networks AMT Relay AMT Relay Multicast Media Server ICDS Unicast Delivery Unicast delivery to end users without AMT multicast capabilities AMT GW AMT GW AMT GW AMT GW 4 3 1 End user requests content and is routed to CDI 2 3 4 CDI scans end user PC for multicast capabilities, enables download of AMT GW, if necessary, and provides multicast source and group address (S,G) to PC End user PC sets up tunnel with nearest AMT Relay and joins multicast stream to receive content CDI determines that multicast is an available technology for this content delivery Content Delivery Intelligence 2 Existing ICDS (1) Component Multicast Service Component Multicast Network Component Unicast Multicast AMT Multicast Signaling/Data Page 6 1 (1) ICDS – AT&T Intelligent Content Distribution Service

7. AT&T AMT Multicast Trials What has worked well Page 7 Quality of AMT multicast perceived as good as unicast Pushing GW client, as needed Pushing appropriate stream to user Anycast Routing for AMT Relays Content Ingest AT&T Multicast Enabled Network AT&T Multicast Enabled Network Non Multicast Enabled Networks AMT Relay AMT Relay Multicast Media Server ICDS Unicast Delivery AMT GW AMT GW AMT GW AMT GW Content Delivery Intelligence Unicast Multicast AMT Multicast Signaling/Data Handling home network environments (e.g. multiple PCs behind NAT, WiFi) Performance & scalability of Relay (Server-based for Trial) Tuning MTU on Media Server to accommodate AMT encapsulation and avoid fragmentation Accounting information uploaded from PC

8. AT&T AMT Multicast Trials Failure Recovery Model Page 8 Content Ingest Non Multicast Enabled Networks AMT Relay AMT Relay Multicast Media Server ICDS Unicast Delivery AMT GW AMT GW AMT GW Unicast Multicast AMT Multicast Signaling/Data 1 2 4 AMT Relay advertises anycast route for Discovery. Once GW discovers Relay, uses its unicast address. AMT GWs can detect Relay failure and “Rediscover” new Relay 1 AMT Relay fails mid-stream Example: 2 AMT GW detects failure and Rediscovers alternate Relay Rejoins stream via alternate Relay 3 3 If Media Player times out before stream resumes, should fail over to unicast in playlist 4 AT&T Multicast Enabled Network Media Player should allow failover from one stream to another on playlist (last one unicast) Multicast media servers could also use anycast for their source address Unicast media server redundancy as today

9. AT&T AMT Multicast Trials Technical Learnings Multicast in General Multicast not universally supported on client devices/players In particular need IGMP V3 Trials so far limited to: Windows XP, Vista Windows Media Player Presence of IGMP V2 causes PC with AMT GW, Relay to downgrade from V3 – incompatible with PIM-SSM AMT-Related Firewall issues blocking AMT Port in corporate environments - Network & PC based Allowing native multicast when available (i.e. AMT GW seamlessly turning on/off as needed) Page 9

10. Technical Learning IGMP V2 Presence on LAN Page 10 AT&T Multicast Enabled Network AT&T Multicast Enabled Network Non Multicast Enabled Networks AMT Relay AMT Relay Multicast Media Server AMT GW AMT GW AMT GW Unicast Multicast AMT Multicast Signaling/Data Home router is IGMP V2 PC reverts to V2 Cannot join (S,G) via PIM-SSM without mapping IGMP V2 Querier Content Ingest ICDS Unicast Delivery 1 2 3 4 Causes PC to revert to V2 Though playlist pushed to PC has (S,G), Media Player issues V2 join (*,G) Unicast delivery is required Without mapping configured, Relay cannot make PIM-SSM join and AMT fails 1 2 3 4 5 5

11. Technical Learning Changing User Network Environments Page 11 Unicast Multicast AMT Multicast Signaling/Data Non Multicast Enabled Networks Multicast Media Server User in office AMT GW should not intercept IGMP joins Corporate Intranet (Multicast capable) User/End Device moves  User/end device moving between environments (native multicast, AMT, unicast-only) Non Multicast Enabled Networks AMT Relay AMT Relay Multicast Media Server AMT GW User at home AMT GW pushed for multicast content AT&T Multicast Enabled Network  Don’t want AMT client to intercept and Discover Relay in native multicast capable setting

12. Opportunities for Further Discussion Improved standardization & development Page 12 Multicast in general Support multicast (IGMP V3) in all devices/media players, OS Media Players should support mid-stream failover in playlist Ability to override IGMP V2 downgrade or selectively ignore V2 queries AAA-like function for multicast Service Assurance AMT-Related Firewalls - consistent approach to allowing AMT port AMT Relay function integrated into network platforms AMT GW function integrated into end user software and transparent to end user Where to integrate AMT GW in home environment? On each client as separate host, On RG, modem, or home router, or On “always-on” host acting as GW

13. Backup Slides Page 13

14. Opportunities for Further Discussion Home Network Configurations Page 14 AT&T Multicast Enabled Network AT&T Multicast Enabled Network Non Multicast Enabled Networks AMT Relay Multicast Media Server AMT GW AMT GW Unicast Multicast AMT Multicast Signaling/Data Variations in home networks: NAT behind modem/router or DMZ/sharing public ip address WiFi/Wired PPPoE on end device or modem, 1483B, etc. Where to integrate AMT GW in home environment? On each client as separate host, On RG, modem, or home router, or On “always-on” host acting as GW (not shown) AMT GW Web TV Box iPhone Broadband Modem/Router RG AMT GW e.g. Android AMT GW AMT GW could be incorporated into end device AMT GW could be incorporated into home GW device AMT GW AMT GW AMT GW OR Broadband Modem/Router AMT Relay Devices – PCs, TVs, mobile phones/PDAs Variations in PC OS, Media players, browsers, firewalls

15. Glossary Page 15 AAAAuthentication, Authorization, and Accounting AMTAutomatic IP Multicast without Explicit Tunnels BRASBroadband Remote Access Server CBBCommon Backbone CDNContent Delivery Network GWGateway HRHome Router ICDSAT&T Intelligent Content Distribution Service IGMPInternet Group Management Protocol NATNetwork Address Translation PIM-SSMProtocol Independent Multicast-Source Specific Multicast RGResidential Gateway WMPWindows Media Player