1. Bill Nickless IETF-55 MBONED draft-ietf-mboned-iesg-gap-analysis-00.txt Internet Multicast Gap Analysis From the MBONED Working Group For the IESG

2. Bill Nickless IETF-55 MBONED Overview and Background IETF-54: MBONED working group recommends that MSDP publish current work as Informational, and shut down. Short term: Document existing MSDP implementations and deployments Long term: Perform “gap analysis” of IP multicast service model, protocols, and deployment

3. Bill Nickless IETF-55 MBONED RFC 1112 Ethernet Multicast for IPv4 Applications –Host Extensions –IPv4 group address range –Static mapping of IPv4 group addresses to Ethernet MAC addresses –Receiver interest notification (IGMP) –Collision-sense multiple-access (CSMA) for multicast IPv4 senders. Transmit at will.

4. Bill Nickless IETF-55 MBONED RFC 1112 Gateways “may exist” for moving IPv4 datagrams between Ethernets Later known as Any Source Multicast (ASM)

5. Bill Nickless IETF-55 MBONED Dense Mode IP Multicast Routing Extend CSMA model to the Internet –Transmit At Will –Traffic-driven forwarding and pruning Does not scale –Meta-stable failure mode –Downstream gateways can’t prune successfully Routing and forwarding mixed

6. Bill Nickless IETF-55 MBONED (Reachability) Protocol Independent Multicast Routing Separate forwarding and routing Unicast reachability: –Where to forward towards destination Multicast reachability: –Where to request from source Examples: RIP, OSPF, BGP, etc.

7. Bill Nickless IETF-55 MBONED Sparse Mode Multicast Routing Forward datagrams when requested by downstream ASM bootstrap: –Dense-mode control plane –Maintains CSMA model from RFC 1112

8. Bill Nickless IETF-55 MBONED Source Specific Multicast Receivers identify both source and group –Explicit request from traffic Fall-out from Sparse Mode Routing User creates source-rooted forwarding trees No need for ASM control plane

9. Bill Nickless IETF-55 MBONED Bursty Source Problem Assumed CSMA model: Transmit At Will. Strictly limited control and announcement traffic –Intended to salvage dense-mode routing from collapse –In sparse-mode context, causes forwarding state flaps –Requires control plane to stay dense –Requires control plane to forward packets

10. Bill Nickless IETF-55 MBONED Co-mingled IP and Ethernet Routing IEEE 802 bridges must become IPv4 aware in order to constrain flooding of IPv4 multicast to all ports. IEEE GARP/GMRP protocol suite for IP multicast on IEEE 802 networks?

11. Bill Nickless IETF-55 MBONED Inter-Domain IP Multicast Exchanges Unicast IP datagrams can traverse an exchange point more than once, if necessary. Multicast IP datagrams cannot traverse an exchange point more than once. Why?

12. Bill Nickless IETF-55 MBONED Overloaded mapping of IP Addresses to IEEE MAC Addresses RFC 1112 IPv4 to IEEE 802 MAC address: 32:1 RFC 2464 (Section 7): 2^96:1 (that’s 79,228,162,514,264,337,593,543,950,336:1) Even IEEE 802 bridges that understand IPv4 IGMP and/or IPv6 MLD still cannot filter unwanted traffic.

13. Bill Nickless IETF-55 MBONED Recommendations to IESG (1/3) Direct MAGMA Working Group to develop a successor to IGMP/MLD –Media agnostic (not Ethernet-driven) –Dynamic mapping of IP group addresses to link-layer point-to- multipoint addresses –Support (*,G), (S,G), and (S,G,upstream) modes –Registration of sources prior to transmission –Implement first at inter-domain exchange points –Not Applicable for IPv4 TTL=1 or IPv6 scopes 0, 1, and 2

14. Bill Nickless IETF-55 MBONED Recommendations to IESG (2/3) Encourage development of protocol to spread knowledge of active sources to interested gateways –Do not actually forward multicast datagrams –Distributed database function Discourage work on IGMP or MLD snooping Encourage use of GARP/GMRP on IEEE 802 networks

15. Bill Nickless IETF-55 MBONED Recommendations to IESG (3/3) Minimum source transmit frequency –Maintain Sparse Mode forwarding state –Eliminate requirement for control plane to carry data

16. Bill Nickless IETF-55 MBONED Questions?