Abstract
Current videoconferencing applications operating on packet networks do not have the capability to gauge the available network capacity prior to requesting additional quality by subscribing to enhancement layers. To minimize transient congestion caused by failed bandwidth-increasing decisions, a router-based agent is developed to assess traffic levels on the receiver's subnet. The agent resides on the receiver subnet's parent router and collects multicast transmission statistics, estimates available multicast bandwidth on the subnet and reports this information to receivers upon request. Prior to joining the enhancement layer, the receiver checks with the agent and video source to ensure that sufficient bandwidth is available. The agent is integrated into the existing CafeMocha videoconferencing framework in a manner complementary to existing congestion avoidance techniques. Bandwidth estimation parameters are experimentally selected to track Variable Bit Rate (VBR) video streams as accurately as possible. The effectiveness of the agent's information during a typical videoconference is demonstrated.
Woodings, Mark Alexander (1997). A router agent for capacity assessment in packet video. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1997 -THESIS -W558.