Fundamental observations on multicast congestion control in the Internet

S.J. Golestani, K.K. Sabnani
1999 IEEE INFOCOM '99. Conference on Computer Communications. Proceedings. Eighteenth Annual Joint Conference of the IEEE Computer and Communications Societies. The Future is Now (Cat. No.99CH36320)  
We study congestion control for one-to-many multicast applications in the Internet and estabtiih a three-way relationship between the choice of regulation parameter (i.e., rate or window size), the requirement to estiiate receiver round trip times, and the type of fairness that may be accomptiihed. In particular, we show that in order to provide TCP-compatible fairness in rate-based regulation, receiver round trip times must be known. However, such a requirement does not exist in windowbased
more » ... ulation. We further show that measurement of receiver roundtrip times in multicast communication, is fundamentally different and more complex than unicast communication, in order to avoid implosion of acknowledgments at the source. A major part of the paper cleats with extending window-based regulation to multicost communications. We show that window-based regulation using a common window-size for the whole session leads to unnecessary restrictions on the throughput. To alleviate this problem, we propose a multicast window scheme using a distinct window size for each receiver, and enforcing it as the Itilt on the number of outstanding packets to that receiver. The complexity of window-based regulation can be defused by a receiver-driven implementation and by consolidation of receiver feedback in successive stages, e.g., using a hierarchical architecture. This hierarchical approach is also useful for scalable consoh idation of receiver feedback in the case of rate-based regulation, and for distributed estimation of receiver round trip times, when such estimation is necessary.
doi:10.1109/infcom.1999.751490 dblp:conf/infocom/GolestaniS99 fatcat:w7afal2gpfgljnhw5yyb463oo4