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The purpose of this research is to design and implement a unified framework for multicast forwardirg that allows the separation of multicast forwarding from multicast routing. Such a framework can provide a unified interface with which different multicast algorithms, host membership algorithms and resource management algorithms can be seemlessly integrated.Multicast is beirg researched in the B-ISDN community in the context of ATM. We believe that there are a number of difficult problems not yet tackled which can be greatly aided by a common framework. In particular, addressing, efficient channel identification and receiver de-multiplexing, route planning and efficient forwarding on multiple paths are all in need of work.Progress:To date, two papers have been published and a third submitted to ACM SIGCOMM '95 Symposium, documenting our work on algorithms, data structures and protocols for multicast in multi service networks.These are: A Unified Framework for Multicast Forwarding, Z. Wang, J.Crowcroft, RN/94/23 in Lecture Notes in Ccmputer Science, Vol. 846 edited by D.Shepherd, G.Coulson, A.Campbell April 1994, Springer-Verlag.This paper examines the issues of implementation and integration in multicast. A framework for multicast forwarding is presented, which separates multicast forwarding from any associated protocols that may affect the forwarding decisions, such as multicast routing, resource management and host membership protocols. This framework allows seamless integration of various associated protocols and provides a unified interface for new development. Issues in QoS Management, Z.Wang, J.Crowcroft, RN/94/47, October 1994, in Proc. of Multi-Services Networks '94, Abirgdon, UK, August 1994. Rutherford Appleton Laboratory, Oxon, UK. In this paper, we examine five important issues in QoS management. Flow specification, Routing, Resource setup, Admission control and Packet scheduling. We also look into implementation and integration issues in a unified packet forwarding engine. QoS Routing for Supporting Resource Reservation, Z.Wang, J.Crowcroft, RN/94/66, October 1994. This paper addresses the problem of QoS routirg support for resource reservation. The implications of source routing and hop-by-hop routing, and the choice for QoS routing metric are examined. An important result is presented on the complexity of path computation subject to multiple constraints. Three new QoS routing and two distributed ones for hop-by-hop routing, are proposed. We are also keeping a watching brief on the Internet Engineering Task Forces efforts in the Inter-domain Multicast Routing working group. A PhD student has been working with the research fellow on this project and the protocol designed there, CBT (published in proceedings of ACM SIGCOMM 93) has been proposed by Fore Systems in the ATM Forum for B-ISDN PNNI Multicast routing.
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