An efficient dynamic multicast agent approach for mobile IPv6 multicast

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An efficient dynamic multicast agent approach for
mobile IPv6 multicast

• ltdraft-zhang-mipshop-multicast-dma-01.txtgt

Enhui Liu Spencer Dawkins Huawei Technologies
Co., Ltd.
Hongke Zhang Bo Shen Bingyi Zhang Beijing
Jiaotong University
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Challenges to Mobile IPv6 Multicast

• Mobile nodes are different from fixed terminals
  for their roaming features. What address is used
  for MNs to join the multicast group membership?
  Home-Address or Care-of-Address?
• One basic method is MIP-BT. Mobile nodes join the
  multicast group with their Home-Address and
  receive the multicast data from their home agent
  via Bidirectional Tunnels. Disadvantages
  triangle routing, long tunnels, large number of
  tunnels, tunnel congregating, packet latency
• Another basic method is MIP-RS. Mobile nodes join
  the multicast group with their Care-of-Address
  and receive the multicast data from their foreign
  agent via Remote Subscription. Disadvantages
  frequent rejoin/leave the multicast group due to
  CoA changes, the resulting frequent multicast
  tree restructuring, handover latency, packet
  loss

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Mobile IPv6 Multicast with DMA

• Concepts
• MSA -- Multicast Subnet Agent, which is the
  access router running multicast protocols in a
  subnet and forwarding the subscribed multicast
  data to the MN that visits the subnet.
• DMA -- Dynamic Multicast Agent, which is the
  current MSA or one of the previous MSAs of the MN
  acting as the leaf router in a multicast delivery
  tree the MN subscribed and forwarding the
  subscribed multicast data to the MN through its
  current MSA.

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Mobile IPv6 Multicast with DMA
Multicast Source
Internet
DMA2 (MSA3)
DMA1 (MSA1)
MSA2
MN_A
MN
MN
MN_A
MN_A
MN
MN moves from DMA1 to MSA2, (Supposing MN within
roaming distance)MN moves from MSA2 to DMA2,
(Supposing MN beyond roaming distance)
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Mobile IPv6 Multicast with DMA

• Main Idea
• The MN joins the multicast group membership with
  its care of address.
• When a MN first subscribes a multicast group G,
  its current MSA becomes its initial DMA.
• Within an acceptable roaming distance, the DMA of
  a MN will not change although its visited MSA
  changes if its visited MSA doesn't yet have the
  group G membership in the subnet.
• Beyond this acceptable roaming distance, the MN's
  DMA will be switched to the new MSA that the MN
  currently is visiting.
• When the MN's current MSA is different from its
  DMA, its current MSA receives the group G
  multicast data from its DMA via a short tunnel,
  and then forwards the multicast data to the MN.

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Mobile IPv6 Multicast with DMA

• When the MN's current MSA is different from its
  DMA,

Source
Multicast Traffic
Multicast Routing Protocol MLD Report Multicast
Traffic
HA
PIM Join Msg
DMA
MSA
MN
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DMA switch decision-making algorithm

• Main Principle
• There shouldnt be any DMA switch for an MN
  within an acceptable roaming distance if the MNs
  visited MSA doesnt yet have the group G
  membership in the subnet.
• Decision-making Algorithm in DMA
• Algorithm is base on movement and distance. It
  could be simple or precise.
• DMA maintains a table to record the MNs recent
  attachment history, which is used for decision
  making.
• In the document we just provide a simple
  algorithm via checking the path increment of the
  recently joined MSA. Its distance-based.

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Conclusion

• The MN joins the multicast group membership with
  its care of address.
• One purpose is to avoid the disadvantage of
  MIP-BT method such as triangle routing, long
  tunnels, large number of tunnels, tunnel
  congregating, packet latency
• The other purpose is to avoid the disadvantage of
  MIP-RS method such as frequent rejoin/leave the
  multicast group due to CoA changes, the resulting
  frequent multicast tree restructuring, handover
  latency, packet loss

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Questions about the draft in the mail list

• (1) What the difference is between your draft
  with other similar drafts?

There are three main different points (a)
There is a algorithm in our draft. The dynamic
and flexible DMA can be selected through this
algorithm. (b) They are different in how to
switch multicast agent. One method is to select
some multicast agent before MN moving. Our method
is to select some MSA before MN moving. However
the MSA not always become a multicast agent. (c)
In our draft, MN do not attend the selection of
multicast agent.
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• (2) In your draft, how do you compute the
  threshold?

The computation of the threshold can be simple or
precise. In the version 00, the threshold is
computed based on the distance of MN movement.

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Thanks for your attention and Suggestion!

• ltdraft-zhang-mipshop-multicast-dma-01.txtgt

Contact info Spencer Dawkins
ltsdawkins_at_futurewei.comgt Hong-Ke Zhang
lthkzhang_at_center.njtu.edu.cngt