Multicast Networking achih@cs.nthu.edu.tw. 2 References Multicast Networking and Applications Miller, C. Kenneth Addison-Wesley, 1999 Computer Networking:

Multicast Networking

achih@cs.nthu.edu.tw

2

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

3

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