Uploaded on

 

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
742
On Slideshare
0
From Embeds
0
Number of Embeds
0

Actions

Shares
Downloads
10
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. AT&T AMT Multicast Trials Patricia McCrink [email_address] 11/09/2009
  • 2. Outline Page
      • 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
  • 4. Automatic Multicast Tunneling Multicast capable and ready Multicast incapable Page PC ATM Broadband Access POPs Aggregation Subscriber Premises Core POPs Typical Current Network Access Router Access Router Core Router Core Router Hub Router BRAS DSLAM RG HR CE CE Native-Multicast End-to-End PC Ethernet Broadband Access POPs Aggregation Subscriber Premises Core POPs Multicast Network - Target Access Router Access Router Core Router Core Router Hub Router BRAS DSLAM RG HR CE CE Native-Multicast Backbone Tunneled-Multicast Access Multicast Network with AMT ATM Broadband Access POPs Aggregation Subscriber Premises Core POPs Access Router Access Router Core Router Core Router Hub Router BRAS DSLAM RG HR CE CE AMT Relay PC AMT Client
  • 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
  • 6. AT&T AMT Multicast Trial Architecture Content Ingest
      • 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 End user requests content and is routed to CDI 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 Page (1) ICDS – AT&T Intelligent Content Distribution Service 4 3 1 2 3 4 2 Existing ICDS (1) Component Multicast Service Component Multicast Network Component Unicast Multicast AMT Multicast Signaling/Data 1
  • 7. AT&T AMT Multicast Trials What has worked well Page
      • Quality of AMT multicast perceived as good as unicast
      • Pushing GW client, as needed
      • Pushing appropriate stream to user
      • Anycast Routing for AMT Relays
      • 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
    Content Ingest
      • 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
  • 8. AT&T AMT Multicast Trials Failure Recovery Model Page Content Ingest Non Multicast Enabled Networks AMT Relay AMT Relay Multicast Media Server ICDS Unicast Delivery AMT GW AMT GW AMT GW
      • 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
      • Example:
      • AMT GW detects failure and Rediscovers alternate Relay
      • Rejoins stream via alternate Relay
      • If Media Player times out before stream resumes, should fail over to unicast in playlist
    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
    Unicast Multicast AMT Multicast Signaling/Data 1 2 4 1
      • AMT Relay fails mid-stream
    2 3 3 4
  • 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
  • 10. Technical Learning IGMP V2 Presence on LAN Page
      • AT&T Multicast
      • Enabled Network
    Non Multicast Enabled Networks AMT Relay AMT Relay Multicast Media Server AMT GW AMT GW AMT GW
      • 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
      • 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
    Unicast Multicast AMT Multicast Signaling/Data 1 2 3 4 1 2 3 4 5 5
  • 11. Technical Learning Changing User Network Environments Page User/End Device moves
      • User/end device moving between environments (native multicast, AMT, unicast-only)
      • Don’t want AMT client to intercept and Discover Relay in native multicast capable setting
    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) 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
  • 12. Opportunities for Further Discussion Improved standardization & development Page
      • 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
  • 14. Opportunities for Further Discussion Home Network Configurations Page
      • AT&T Multicast
      • Enabled Network
    Non Multicast Enabled Networks AMT Relay Multicast Media Server AMT GW AMT GW
    • 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
    Unicast Multicast AMT Multicast Signaling/Data
  • 15. Glossary Page AAA Authentication, Authorization, and Accounting AMT Automatic IP Multicast without Explicit Tunnels BRAS Broadband Remote Access Server CBB Common Backbone CDN Content Delivery Network GW Gateway HR Home Router ICDS AT&T Intelligent Content Distribution Service IGMP Internet Group Management Protocol NAT Network Address Translation PIM-SSM Protocol Independent Multicast-Source Specific Multicast RG Residential Gateway WMP Windows Media Player