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AT&T AMT Multicast Trials

AT&T AMT Multicast Trials. Patricia McCrink pmccrink@att.com 11/09/2009. Outline. AT&T Trial Activity – AMT Multicast Motivation Overview of Trial Technical Learnings Opportunities for Further Discussion Improved standardization & development. AT&T AMT Multicast – Motivation.

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AT&T AMT Multicast Trials

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

  2. Outline • 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

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

  5. AT&T AMT Multicast TrialsOverview • 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 perspectiveIntegrated 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)

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

  7. Unicast Multicast AMT Multicast Signaling/Data AT&T AMT Multicast TrialsWhat has worked well Content Ingest ICDS Unicast Delivery • Quality of AMT multicast perceived as good as unicast • Pushing GW client, as needed • Pushing appropriate stream to user • Anycast Routing for AMT Relays Multicast Media Server • AT&T Multicast • Enabled Network AMT GW AMT Relay Content Delivery Intelligence AMT GW • Accounting information uploaded from PC • 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 Non Multicast Enabled Networks AMT Relay AMT GW AMT GW

  8. Unicast Multicast AMT Multicast Signaling/Data 1 4 3 3 2 1 4 2 AT&T AMT Multicast TrialsFailure Recovery Model ICDS Unicast Delivery Content Ingest • 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 Multicast Media Server AMT GW AT&TMulticastEnabledNetwork AMT Relay • 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 AMT GW AMT Relay Non Multicast Enabled Networks AMT GW • Example: • Rejoins stream via alternate Relay • AMT GW detects failure and Rediscovers alternate Relay • If Media Player times out before stream resumes, should fail over to unicast in playlist • AMT Relay fails mid-stream

  9. AT&T AMT Multicast TrialsTechnical Learnings • Multicast in General • Multicast not universally supported on client devices/playersIn 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)

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

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

  12. Opportunities for Further DiscussionImproved standardization & development • 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

  14. Unicast Multicast AMT Multicast Signaling/Data Opportunities for Further DiscussionHome Network Configurations Multicast Media Server • 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) • AT&T Multicast • Enabled Network AMT GW AMT Relay • Variations in home networks: • NAT behind modem/router or DMZ/sharing public ip address • WiFi/Wired • PPPoE on end device or modem, 1483B, etc. AMT GW AMT Relay Non Multicast Enabled Networks • Devices – PCs, TVs, mobile phones/PDAs • Variations in PC OS, Media players, browsers, firewalls BroadbandModem/Router RG BroadbandModem/Router AMT GW AMT GW Web TVBox AMT GW AMT GW AMT GW AMT GW iPhone e.g. Android AMT GW could be incorporated into home GW device AMT GW could be incorporated into end device OR

  15. Glossary

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