Evaluation of PMIPv6 Base Multicast Support Drafts Stig Venaas Behcet Sarikaya November 2009

1. Evaluation of PMIPv6 Base Multicast Support Drafts Stig VenaasBehcet SarikayaNovember 2009 Multimob WGIETF 76

2. Charter Item • Some forms of multicast support can, however, be built in the involved nodes by using existing capabilities of multicast protocols and the underlying mobility protocols. The first task of the working group is to document such solutions for PMIPv6. • This work will not require any additions or changes to message types and parameters specified in RFC 5213 • Must assume an unmodified mobile host • The work will employ the remote subscription model. This is a mechanism by which a mobile node joins a multicast group and receives multicast data forwarded via the local mobility anchor

3. Current Drafts • draft-schmidt-multimob-pmipv6-mcast-deployment-02 • draft-krishnan-multimob-pmip6basicmcast-solution-00 • draft-sijeon-multimob-mms-pmip6-01 • draft-zuniga-multimob-smspmip-00 • draft-contreras-multimob-msd-00

4. draft-schmidt-multimob-pmipv6-mcast-deployment-02 • MLD Proxy at the MAG • Only one registration (aggregated join) is sent to LMA as multicast router for each group • Avalanche is avoided because packet duplication is done at MAG • MN handover to another MAG, MN has to send Join to the new MAG which may send aggregated join to LMA • Two MNs using two LMAs join the same group leads to MAG receiving duplicate data packets (should we call this tunnel convergence problem?)

5. draft-krishnan-multimob-pmip6basicmcast-solution-00 • DSMIPv6-like base multicast support protocol • Multicast state is kept at LMA • LMA duplicates multicast data and sends it encapsulated to MAG -> avalanche • MN handover to another MAG, MAG has to modify Proxy-CoA for this MN using PBU/PBA • MAG decapsulates twice • IGMP is also supported • How can LMA identify MNs based on MLD source addresses? • How can MAG send link local MLD/IGMP packets to LMA avoiding TTL issues?

6. draft-sijeon-multimob-mms-pmip6-01 • MAG is MLD Proxy • MLD Proxy communicates with MR not necessarily located at LMA • This leads to “direct routing” of multicast data which avoids “tunnel convergence” problem (not avalanche problem) • MN handover to another MAG, instead of MN sending Join, P-MAG to N-MAG context transfer is used to also transfer multicast state

7. draft-zuniga-multimob-smspmip-00 • MAG is MLD Proxy • Section 3 LMA is like in draft-schmidt-multimob-pmipv6-mcast-deployment-02 • Section 4 Multicast LMA is introduced • If MN is multicast capable, PBU is sent to multicast LMA to establish “multicast tunnel” • Multicast LMA avoids “tunnel convergence” problem • MN handover to new MAG either MN sends join to nMAG or nMAG receives “handover trigger” with MN multicast context

8. draft-contreras-multimob-msd-00 • MAG is MLD Proxy in one scenario • MAG is multicast router in another scenario • For MLD Proxy scenario, “tunnel convergence” is not addressed • For MLD scenario, MN handover to new MAG, context transfer from pMAG is assumed to transfer MN multicast state to nMAG • For multicast router scenario, no “tunnel convergence” problem but MN handover to new MAG then pMAG tunnels multicast data to LMA and LMA redirects it to nMAG until state is established

9. Evaluation - draft-contreras-multimob-msd-00 • Does not prescribe a certain method for MAG • It covers two alternatives equally • Large part of it discusses context transfer • Not a base solution type of document?

10. Evaluation - draft-schmidt-multimob-pmipv6-mcast-deployment-02 • MAG as MLD Proxy solution • MN’s LMA as multicast router • It does not address the problems associated with this approach, i.e. “tunnel convergence” and MN handover • Join after handover a protocol extension of IGMP/MLD? • This draft is a base solution for MAG as MLD Proxy solution

11. Evaluation - draft-sijeon-multimob-mms-pmip6-01 • MAG as MLD Proxy • MR not at LMA which solves “tunnel convergence” problem • MN handover problem is solved by context transfer • Context transfer is PMIPv6 extension

12. Evaluation - draft-zuniga-multimob-smspmip-00 • MAG as MLD Proxy • Regular LMA as multicast router solution has “tunnel convergence” problem and MN handover problem • Multicast LMA solution solves “tunnel convergence” problem and MN handover problem is dealt with using handover trigger or context transfer

13. Evaluation – Remote subscription • The charter requires remote subscription to be used in PMIPv6 base solution • MAG as MLD proxy in draft-schmidt-multimob-pmipv6-mcast-deployment-02, draft-sijeon-multimob-mms-pmip6-01 and draft-zuniga-multimob-smspmip-00 is it or not remote subscription because MAG sends an aggregate join to LMA?

14. Evaluation – IPv4 support • draft-krishnan-multimob-pmip6basicmcast-solution-00 has explicit IPv4 support • draft-schmidt-multimob-pmipv6-mcast-deployment-02 only mentions that MAG as IGMPv3 proxy analogous to MAG as MLD proxy • draft-sijeon-multimob-mms-pmip6-01 also assumes IGMP proxy at MAG operation is analogous • draft-zuniga-multimob-smspmip-00 does not mention IGMPv3 operation explicitly but MLD and IGMP are always mentioned together • draft-contreras-multimob-msd-00 does not even mention IGMP

15. What Should be in WG Draft? • Depends on which approach is taken • Multicast not locally available (no MLD Proxy at the MAG) forward IGMP/MLD to LMA, decap multicast data from LMA? • IGMP/MLD Proxy at the MAG?

16. Thank you