Paper #20

Topology Sensitive Congestion Control
for Real-Time Multicast

Srinivasan Jagannathan, Kevin C. Almeroth
& Anurag Acharya
University of California Santa Barbara


The multicast-based distribution of streaming media is conjectured to be an important component of future net-work services. Congestion control has emerged as a major hurdle in the large-scale deployment of such services. Heterogeneity in transmission media, end-systems, and traffic flows have significantly increased the complexity of the problem. Researchers have sought to address the problem through such mechanisms as layered encoding and TCP-style formulae. The end-to-end paradigm has been the guiding principle for these approaches. In parallel, many tools are being developed that provide snapshots of network internals. Of interest to us are tools that accurately construct or estimate the topology of a multicast tree. In this paper, we explore whether these tools can assist in providing congestion control for real-time multicast. Through this exercise we find that the multicast tree topology, if available, can be used to regulate the flow of streams. In this paper, we seek to understand the additional benefits of using this information by focusing on the extreme case where the complete tree topology is known. We develop an algorithm which uses this information and layered streams to provide robust congestion control. We evaluate our algorithm using ns, the network simulator. Our results show that our algorithm is robust and converges to "fair" subscription levels for each receiver.
Download a copy of this paper in either: Compressed PostScript (42K) - or - PDF (83K) format.

Back to the NOSSDAV 2000 On-Line Proceedings.


- Last revised: Weds Jun 27 20:56:29 EDT 2000