FMIPv6 Extension for Multicast Handover

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FMIPv6 Extension for Multicast Handover

• Frank Xia
• xiayangsong_at_huawei.com

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Problem Statement -1

• A mobile node joins a multicast group via a
  local multicast router on the foreign link being
  visited.
• Mobile IPv6 does not provide mechanisms to enable
  local multicast session to survive hand-off

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Problem Statement - 2

• Fast Handovers for Mobile IPv6 only deals with
  unicast traffic not multicast traffic
• Major application is in mobile IPTV deployment
• Such as every city has their own TV programs
  provided to users

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Problem Statement - 3

• HoA based multicast membership
• Requires HA tunnelling
• CoA based multicast membership
• Local distribution hence improves performance
• Especially important in mobile IPTV

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Proposed Solution
PAR
NAR
MN
RtSolPr
1 FBU/HI convey an MNs multicast information for
an NAR to start building multicast delivery
tree 2 PAR buffers multicast traffic during
handover 3 NAR delivers the buffered traffic as
soon as the MN attaches to the NAR
PrRtAdv
FBU
HI
HAck
FBack
FBack
Disconnect
Forward packets (include multicast
traffic)
Connect
FNA
deliver packets (include multicast traffic)
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Mailing List Discussions-1

• Building multicast delivery tree dynamically or
  statically?
• Static configuration is limited and restricts
  mobility and not scalable.
• We need dynamic configuration capability in the
  system which can be done with a small extension
  to FMIP as the draft explains
• How PAR knows when NAR has already constructed
  the multicast tree so PAR can stop forwarding
  multicast data ?
• Probably no need to have a special mechanism
  since even if MN had two copies of a packet, it
  would not be harmful to the upper layers
• How to maintain the tunnel for multicast traffic?
• One tunnel is used not only for unicast traffic
  but also multicast stream. The tunnel is
  constructed and aged according to the standard
  FMIPv6. The lifetime in FBU message can be
  configured to a larger value to accommodate
  multicasting.

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Mailing List Discussions-2

• Is it necessary to tunnel the multicast packets
  from PAR to NAR?
•   Two purposes for tunneling multicast traffic
• 1) buffering the multicast traffic during
  handover
• 2) making full use of the old multicast
  deliver tree in PAR before a new tree built in
  NAR
• Should FNA also get MGI option?
• Yes, we will add this in the next revision
• Should we change the signaling?
• Suggestion was NAR sends join to PAR upon
  handover and then sends prune after NAR joins the
  tree. Why? Join to PIM RP by NAR may take longer.
• PAR is a leaf router for the multicast delivery,
  it is not proper to build multicast tree for NAR.

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Next Steps

• Issue a revision based on the comments
• What does WG think about the problem?

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Thank You. Questions?