Extensions of the ATM Forum Available Bit Rate (ABR) Service to point-to-multipoint connections will be discussed. Both point-to-multipoint (1 source and n receivers) and multipoint-to-point (n sources and 1 receiver) will be covered.
ABR traffic management for point-to-multipoint connections entails that the source be controlled to the minimum rate supported by all the leaves of the multicast tree. A number of algorithms have been developed for extending ABR congestion avoidance algorithms to perform the feedback consolidation operation. In this talk, we discuss the various design options and implementation alternatives for the consolidation algorithms, and propose a number of new algorithms.
In a multipoint-to-point connection, multiple senders send data to the same destination. The multipoint-to-point connection can be implemented as a shared tree, where traffic from multiple branches is merged into the same stream after every merging point. If the same VPI/VCI values are used by all senders in the multipoint-to-point VC, it is impossible for the network to determine any sender-specific characteristics (such as the sender rate and whether it is bottlenecked at this link). Thus ABR multipoint traffic management becomes complex, since per-VC (or per-flow) accounting is no longer equivalent to per-source accounting. We design and simulate a switch scheme that achieves fairness among the senders in both point-to- point and multipoint-to-point connections.
This talk covers the following topics:
Presentation slides in Adobe Acrobat Format: 1 slide/page
Congestion Control in ATM Networks: Recent Results and Open Problems
Design and Evaluation of Feedback Consolidation for ABR Point-to-Multipoint
Feedback consolidation algorithms for ABR point-to-multipoint connections
Feedback Consolidation Algorithms for ABR Point-to-Multipoint Connections
IP Multicasting: Concepts, Algorithms, and Protocols; IGMP, PRM, CBT, DVMRP,
Rate Based Schemes: Mistakes to Avoid