Multicast Transport Protocols: A Survey and Taxonomy

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Multicast Transport Protocols A Survey and
Taxonomy

• Author Katia Obraczka
• University of Southern California
• Presenter Venkatesh Prabhakar

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Contents

• Introduction
• Taxonomy
• Survey of Multicast Transport Protocols
• Conclusion

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Introduction

• Earlier mechanisms
• General solutions to the group communication
  problem
• Recent trends focus on
• Multipoint interactive applications
• Data Dissemination applications

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Taxonomy

• Data Propagation
• Reliability Mechanism
• Repair request
• Feedback Control
• Retransmission
• Flow and Congestion Control
• Locus of Control
• Ordering
• Group Management
• Target Application

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Taxonomy

• Data Propagation
• Multicast, some work with unicast too
• Reliability Mechanism
• Receiver initiated through NACKs
• Special site for feedback control
• Avoiding losses
• Forward Error Correction
• Hybrid approach

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Taxonomy

• Repair request and Retransmission
• Point to Point or to the whole group
• NACK suppression
• Local recovery
• Feedback Control
• Structure based - designated site or control
  structure
• Timer based probabilistic feedback suppression

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Taxonomy

• Flow and Congestion Control
• Rate, window and token based schemes
• Layered Multicast Encoding to different layers
• Forward Error Correction techniques
• Representative based congestion control
• Control
• Distributed Vs Centralized
• Ordering
• Assigning sequence numbers

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Taxonomy

• Group Management
• Implicit or Explicit
• Variation Authorization only while joining
• Target Application
• Generic ones
• Delay sensitive real time services
• Reliable transfers
• Resilience as opposed to reliability

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General Purpose Protocols

• Reliable Broadcast Protocol
• Multipoint communication between sites connected
  by a local broadcast network
• Messages multicast through a token site
• Token site multicasts ACKs
• NACKs sent to Token site upon Packet loss
• Token site rotated among group members

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General Purpose Protocols

• Multicast Transport Protocol
• Reliable and globally ordered delivery
• Group Master coordinates members
• Transmits tokens which provide ordering,
  congestion control
• Group membership allowed only when all transmit
  tokens are with the master
• Retransmission NACK based
• Uses fixed size transmission window

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General Purpose Protocols

• Reliable Multicast Protocol
• Name service advertises multicast groups, and
  flow and congestion control schemes
• Dynamic group updation
• TCP-like congestion control Timers, ACKs and
  NACKs used to control window size
• Reliability through multicasting NACKs

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General Purpose Protocols

• Xpress Transport Protocol
• Designed to support a wide range of applications
• Explicit multicast group management protocol
  (MGM)
• TCP-like fully reliable delivery, UDP-like best
  effort delivery and Fast NACK modes.
• Sender can select ACK frequency
• Window and rate based flow control

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General Purpose Protocols

• Uniform Reliable Group Communication Protocol
• Reliable ordered communication though a
  coordinator
• All sites keep history and coordinator knows the
  most up-to-date site
• Reliable Multicast Framework
• Provide framework to develop multicast protocols
  for various applications

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Support for Multipoint Interactive Applications

• Multicast Transport Protocol-2
• Immediate joins
• Master recovery
• Dynamic group parameter adjustment
• Real-Time Transport Protocol
• Does not assure ordered reliable delivery
• RTCP used for control information
• Avoids packet losses using probabilistic polling
  of set of receivers to compute rates

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Support for Multipoint Interactive Applications

• Scaleable Reliable Multicast
• Distributed protocol
• Group management by join and session messages
• Log Based Receiver-Reliable Multicast
• Logging server (LS) logs all packets
• LS ACKs senders and Receivers NACK LS
• Secondary logging servers used as proxies and for
  local recovery

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Support for Multipoint Interactive Applications

• Reliable Adaptive Multicast Protocol
• NACK based reliable delivery
• Burst and idle modes
• Rate based flow control
• Transport Protocol for Reliable Multicast
• Interactive Multimedia applications
• Group membership handled by application
• Multicasting NACKs and probabilistic NACK
  suppression

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Support for Data Dissemination Services

• Muse
• Posting multicast news articles
• Uses cryptographic checksums and signatures on
  data for authentication
• Keep-alive messages
• Multicast Dissemination Protocol
• Fragments files to MDUs
• Recovery by source asking receivers for
  retransmission requests at end of transmission

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Support for Data Dissemination Services

• Adaptive File Distribution Protocol
• Group management done by a designated group
  secretary
• No recovery mode for site failures or network
  partitions
• Tree-Based Multicast Transport Protocol
• Control Tree Structure Domain manager
• Max tree degree defined
• ACKs and NACKs limited in scope

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Support for Data Dissemination Services

• Reliable Multicast Transport Protocol
• Control Tree Designated Receivers
• Reclaim buffers on ACKs from children
• Window based flow control
• Multicast File Transfer Protocol
• Modes Unicast, Broadcast and Multicast
• Two pass Data Transmission protocol
• Open and closed Group Management

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Interactivity Vs Reliabilty

• Resilient multicast delivery model
• Structure Oriented Resilient Multicast
• Dynamic distribution graph
• Unicasts NACK to each parent
• Extended Ring Search (ERS) to look for parents
• Nodes measure parents performance and react to it
• Mechanism to avoid loops provided

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Conclusion

• Summary
• Survey and Classification of most Multicast
  Transport Protocols presented
• Multicast Congestion Control big research area
• My Opinion
• Provides good pointers to the existing protocols
• Emphasizes the Application Level Framing trend in
  Multicast Transport Protocols