The talk describes some recent work whose goal is to find a good algorithm to solve the following problem: how can one meet the bandwidth and delay requirements of a multicast call and at the same time make best use of network resources?

It reviews IP multicast protocols such as DVMRP, PIM, CBT and CSM, and formulate a problem called the QoS Multicast Conferencing Problem.

The QoS Multicast Conferencing Problem is approached by first solving a related problem called the Constrained Time Steiner Problem. The Constrained Time Steiner problem is to find an optimal cost shared tree subject to delay constraints. A new approach is described for solving this latter problem using Lagrangian relaxation techniques and a new metric developed by the speaker called delta diameter.

Finally, it describes how the QoS Multicast Conferencing Problem can be translated into the Constrained Time Steiner Problem using ideas derived from PGPS / Weighted Fair Queuing and its derivatives.

Biography of Speaker: Sudhir Aggarwal is a professor and chairman of the Computer Science department at SUNY Binghamton. His research interests are computer networks, distributed systems, information retrieval from the WWW, protocol specification and validation, and real-time systems.