multicast: wired to wireless
DESCRIPTION
Multicast: Wired to Wireless. Hrishikesh Gossain Carlos de Morais Cordeiro Dharma P. Agrawal IEEE Communication Magazine June 2002 資工所 蔡家楷. Outline. Introduction Multicast Support Multicast in the Internet Multicast in Wireless Mobile Environment Conclusion & Future Direction. - PowerPoint PPT PresentationTRANSCRIPT
Multicast: Wired to Wireless
Hrishikesh Gossain Carlos de Morais Cordeiro
Dharma P. AgrawalIEEE Communication Magazine
June 2002 資工所 蔡家楷
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Outline
Introduction Multicast Support Multicast in the Internet Multicast in Wireless Mobile
Environment Conclusion & Future Direction
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Introduction
Provide efficient way of services for application Real-time Class 、
Multiplayer on line gaming
IPv4 reserved Class D address to support multicasting
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Multicast Support
Initial Support Multicast-capable routers (MRouters) Dedicated Tunnels Multicast backbone (MBone)
Presently No need dedicated tunnels Native multicast
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Multicast Support
Multicast Group Membership IP supports dynamic joining and
leaving of a group by IGMP (Internet Group Management Protocol)
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Multicast Support
Packet Forwarding Multicast forwarding algorithm
Source-basedCore-based
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Source-based
RPB – Reverse Path Broadcasting Spanning tree is created for each
(source,group) pair TRPB – Truncated Reverse Path
Broadcasting Manage group by IGMP Prune non-leaf router
Source
Membership
Router
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Source-based
RPM – Reverse Path Multicasting Spans only to routers and subnetwork
with group member
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Core-based
CBT - Core Based Tree Build a single shred multicast tree with
a core router All packets are forwarded through the
core Group managed by the core Receiver-oriented
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Multicast in the Internet
Routing Protocol DVMRP – Distance Vector Multicast
Routing ProtocolSource-basedFirst packet forward to entire interfacePrune messageGraft message
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Multicast in the Internet
Routing Protocol MOSPF – Multicast Extensions to OSPF
Unicast routing information obtained from OSPF
Group membership obtained from IGMPBuild a multicast forwarding tree on demand f
or each (source,group) pairHierarchical routing – hosts are partitioned int
o autonomous system (ASs)
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Multicast in the Internet
Routing Protocol PIM-SM - Protocol-Interdependent
Multicast-Sparse ModeSupport multicast independent of any
underlying unicast routing protocolFor sparse distributed receiver on Internet
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Multicast in the Internet
RP – Rendezvous pointForwarding packets destined for the multicast
group DR – Designated router
Handles multicast group membership message in it’s domain
Group
RPMS
M
S
DR
MMDR
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Multicast in Wireless Mobile Environment
Issue in Mobile Environment Multicast forwarding algorithm Dense or sparse mode protocols QoS provisioning
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Multicast in Wireless Mobile Environment
Proposals for multicast over MIP by IETF Remote Subscription
An MH resubscribe to the multicast group each time it moves to a new foreign network
Frequent resubscription may lead to lost packets Bidirectional Tunneling
Using unicast Mobile IP tunnels from their HasRequires the HA of an MH to be a multicast router
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Multicast in Wireless Mobile Environment
Multicast support using Mobile IP (MoM) Tunnel convergence problem
Select one HA as DMSP (Designated Multicast Service Provider)
Packet loss when MH handoffSelect more than one DMSP
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Multicast in Wireless Mobile Environment
Multicast for Mobility Protocols (MMP) Provide fast and efficient handoffs for
MH Combines Mobile IP and CBT
MIP for controls communication up to the foreign network
CBT for movement of hosts inside foreign network
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Multicast in Wireless Mobile Environment
MMP working flow BS send beacon include multicast CoA According CoA, MH send join message
to BS BS transmits a CBT join request to the
Core The core request the HA of MH to
replace the CoA to its own address
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Multicast in Wireless Mobile Environment
MMP drawback Assumes a large-scale deployment of mult
icast-capable routers in each domain Not protocol-indendpent
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Reliable wireless Multicast Protocols
RMDP Protocol – Reliable Multicast Data Distribution Protocol FEC (Forward error Control) & ARQ
(Automatic Repeat Request) A data object to be transmitted is a file Split file into packets, and encoded to
transmission
Drawback: encoding/decoding done by software, affect performance
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Reliable wireless Multicast Protocols
RM2 Protocol – Reliable Mobile Multicast Used for both wired & wireless Rely on
IGMP: to manage group membership IETF’s Mobile IP to support CoA
MADCAP – Multicast Address Dynamic Client Allocation Protocol
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Reliable wireless Multicast Protocols
RM2 Protocol NACK for request retransmitting
NACK: Negative acknowledgements RS manage retransmission for
fixed/mobile user or mixture of them
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Conclusion & Future Direction
There is no one-size-fits-all protocol for multicast Both wired & wireless multicast
proposal designed to cope with specific scenario
QoS, Security and so on