Multicast Networking - National Tsing Hua University

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Transcript Multicast Networking - National Tsing Hua University

Multicast Networking
[email protected]
References
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Multicast Networking and Applications
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Computer Networking: A Top-Down Approach
Featuring the Internet
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Miller, C. Kenneth
Addison-Wesley, 1999
James F. Kurose, Keith W. Ross
http://gaia.cs.umass.edu/kurose/Contents.htm
RFC
2
Introduction
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Unicast protocols
Multicast protocols
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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
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address indirection
class D
224. 0. 0. 0 ~ 239.255.255.255
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IPv6
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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
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IGMP
Multicast routing protocol
Transport layer multicast protocol
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Reliable multicast protocol
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IGMP
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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
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RFC 1112
Nearest router
Query messages
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Periodically from router to hosts
Time To Live of 1
Membership reports from hosts
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Random back-off to avoid
report messages implosion
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IGMP v2
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RFC 2236
Membership query
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General group
Specific group
Membership report
Leave group
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IGMP v3
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Internet draft
Select only specific sources of multicast
traffic to receive
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Inclusion group-source report messages
Exclusion group-source report messages
Leave group messages
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Specify the IP addresses of any source-group
pairs it wishes to leave
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Multicast Routing Protocols
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Group-shared tree
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Steiner tree problem
Source-based tree
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Distance vector
Link state
Shared tree
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DVMRP
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RFC 1075
Distance vector algorithm
Reverse path forwarding(RPF)
Pruning
grafting
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MOSPF
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RFC 1584
Link-state advertisements
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Complete topology information
Edge routers with attached hosts belonging to
various multicast groups
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Protocol Independent Multicast-Dense
Mode
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Internet draft
Flood-and-prune
Similar to DVMRP
Protocol independent
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Core-Based Trees
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RFC 2201,2189
Single core
Join
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JOIN_REQUEST
JOIN_ACK
Maintain
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ECHO_REQUEST
ECHO_REPLY
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Protocol Independent Multicast-Sparse
Mode
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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
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Interior gateway protocol (IGP)
Exterior gateway protocol (EGP)
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Border Gateway Multicast Protocol (BGMP)
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Internet draft
Group-shared tree approach
Set up roots by MASC
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Wide Area Networks
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Asynchronous transfer mode
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Meshes of point-to-multipoint PVCs
ATM-level multicast servers (MCS)
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One-way satellite
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Reliable Multicast Technology
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TCP : point-to-point (unicast)
UDP : multicast
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Research Activities and Topics
in Reliable Multicast
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Request implosion
Duplicate replies
Recovery latency
Recovery isolation (exposure)
Adaptability to dynamic membership
change
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Reliable Multicast Protocols
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Create a generalized reliable multicast
transport layer that can handle all
reliable multicast applications
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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
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Scalable Reliable Multicast (SRM)
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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)
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Designated Receivers (DRs)
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Collect status messages from nodes in a local
RMTP domain
Provide repairs
RMTP+
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Transmit window
Bit mask (selective repeat retransmission)
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RMTP
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Specialized Reliable Multicast
Protocols
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Reliable Adaptive Multicast Protocol
(RAMP)
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Group sizes less than 100, timeliness
RFC 1458
Break up the data sent into bursts
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Burst mode
Idle mode
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Multicast File Transfer Protocol (MFTP)
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Internet draft
NAK-based
Block as large as possible
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