Markdown Version | Session Recording

Session Date/Time: 24 Jul 2024 22:30

mboned

Summary

The mboned working group session at IETF 120 in Vancouver covered several important topics related to multicast deployment and technology. Presentations included adaptive unicast to multicast forwarding, multicast options in segment routing networks, an update to RFC 1112 (the original IP multicast specification), and open caching and multicast CDNs. Key discussion points revolved around the applicability of different multicast solutions in various network scenarios, the challenges of multicast adoption, and potential mechanisms for incentivizing multicast relay deployment.

Key Discussion Points

• Adaptive Unicast to Multicast Forwarding:
  • The presented mechanism aims to address bandwidth pressure in carrier networks due to redundant unicast traffic for services like live video.
  • The approach involves converting unicast packets to multicast within the carrier network and then reverting to unicast at the edge.
  • Discussion focused on how the Ingress PE identifies traffic suitable for multicast conversion, particularly when dealing with encrypted unicast flows, and whether AMT (Automatic Multicast Tunneling) could address the same problem space.
• Multicast Options in Segment Routing Networks:
  • The presentation outlined options for multicast deployment in SR networks, focusing on non-source-routed options.
  • The options included ingress replication, beer (Bit Index Explicit Replication), and controller-calculated trees.
  • Discussion highlighted the trade-offs between different approaches and the challenges of beer deployment.
• RFC 1112 Update:
  • An update to the original IP multicast specification was presented with the main goal of removing IGMP version 1
  • Multicast is now ALA Multicast, a full standard but not over the internet but in controlled networks.
• Open Caching and Multicast CDNs:
  • The presentation described an architecture for multicast CDNs that addresses the challenges of scaling video delivery in unicast-centric networks.
  • The architecture leverages open caching, adaptive HD proxies, and a capacity marketplace.
  • Discussion covered the applicability of AMT within this architecture, and also incentivization mechanisms for AMT relay deployment.
• Overall Discussion:
  • The main problems of multicast routing and addressing technologies for video delivery were discussed.

Decisions and Action Items

• Adaptive Unicast to Multicast Forwarding: The presenter was encouraged to take the discussion to the mailing list to further refine the use cases and address concerns about the mechanism's applicability.
• Multicast Options in Segment Routing Networks: The presenter will solicit feedback on the list.

Next Steps

• Continue discussions on the mailing list for both adaptive unicast to multicast forwarding and multicast options in segment routing networks.
• The presenter of the open caching architecture will provide a technical document to aid further discussion.