Multicast Networking [email protected]
Dec 21, 2015
Multicast Networking
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References Multicast Networking and Applications
Miller, C. Kenneth Addison-Wesley, 1999
Computer Networking: A Top-Down Approach Featuring the Internet James F. Kurose, Keith W. Ross http://gaia.cs.umass.edu/kurose/Contents.htm
RFC
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Introduction Unicast protocols Multicast protocols
From one or more senders to a group of receivers
bulk data, streaming continuous media, shared data applications, data feeds, interactive gaming
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Multicast applications
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Multicast group address indirection class D
224. 0. 0. 0 ~ 239.255.255.255
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IPv6 128 bits flgs: three higher-order bits are set to
zero scop: 0~F
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Multicast address allocation
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Network layer multicast protocol IGMP Multicast routing protocol
Transport layer multicast protocol Reliable multicast protocol
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IGMP Joining particular multicast group is
receiver-initiated using the Internet Group Management Protocol (IGMP)
A dialog that occurs between routers supporting multicast routing and hosts on a subnet attached to that router
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IGMP v1 RFC 1112 Nearest router Query messages
Periodically from router to hosts Time To Live of 1
Membership reports from hosts Random back-off to avoid report messages implosion
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IGMP v2 RFC 2236 Membership query
General group Specific group
Membership report Leave group
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IGMP v3 Internet draft Select only specific sources of
multicast traffic to receive Inclusion group-source report messages Exclusion group-source report messages
Leave group messages Specify the IP addresses of any source-
group pairs it wishes to leave
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Multicast Routing Protocols Group-shared tree
Steiner tree problem Source-based tree
Distance vector Link state Shared tree
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DVMRP RFC 1075 Distance vector algorithm Reverse path forwarding(RPF) Pruning grafting
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MOSPF RFC 1584 Link-state advertisements
Complete topology information Edge routers with attached hosts
belonging to various multicast groups
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Protocol Independent Multicast-Dense Mode Internet draft Flood-and-prune Similar to DVMRP Protocol independent
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Core-Based Trees RFC 2201,2189 Single core Join
JOIN_REQUEST JOIN_ACK
Maintain ECHO_REQUEST ECHO_REPLY
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Protocol Independent Multicast-Sparse Mode RFC 2117 Rendezvous point Encapsulate data and unicast to the
RP Switch from a group-shared tree to a
source-specific tree
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Interdomain Multicast Routing Interior gateway protocol (IGP) Exterior gateway protocol (EGP)
Border Gateway Multicast Protocol (BGMP)
Internet draft Group-shared tree approach Set up roots by MASC
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Wide Area Networks Asynchronous transfer mode
Meshes of point-to-multipoint PVCs ATM-level multicast servers (MCS)
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One-way satellite
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TCP : point-to-point (unicast) UDP : multicast
Reliable Multicast Technology
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Research Activities and Topics in Reliable Multicast Request implosion Duplicate replies Recovery latency Recovery isolation (exposure) Adaptability to dynamic
membership change
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Reliable Multicast Protocols Create a generalized reliable
multicast transport layer that can handle all reliable multicast applications timeliness, packet ordering, error
correction, high scalability Focus the reliable multicast protocol
on solving the needs of particular applications
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Generalized Reliable Multicast Protocols Scalable Reliable Multicast (SRM)
Repair by any receiver that has the data to achieve scalability by reducing administrative back-traffic to the source
Suppression of duplicate requests via a random time period
A random back-off timer is used before a repair is sent
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No scope limit (exposure)
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Reliable Multicast Transport Protocol (RMTP) Designated Receivers (DRs)
Collect status messages from nodes in a local RMTP domain
Provide repairs RMTP+
Transmit window Bit mask (selective repeat
retransmission)
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RMTP
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Specialized Reliable Multicast Protocols Reliable Adaptive Multicast
Protocol (RAMP) Group sizes less than 100, timeliness
RFC 1458 Break up the data sent into bursts
Burst mode Idle mode
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Multicast File Transfer Protocol (MFTP) Internet draft NAK-based Block as large as possible