Multicast Transport Protocols: A Survey and Taxonomy
Author: Katia ObraczkaUniversity of Southern
CaliforniaPresenter: Venkatesh
Prabhakar
Introduction Earlier mechanisms
General solutions to the group communication problem
Recent trends focus on Multipoint interactive applications Data Dissemination applications
Taxonomy Data Propagation Reliability Mechanism Repair request Feedback Control Retransmission Flow and Congestion Control Locus of Control Ordering Group Management Target Application
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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