Quality of service in TCP/IP networks: a DiffServ testbed

An implementation of the weighted fair queue algorithm on a Pentium/Windows 2000 platform is presented with preliminary test results. This is part of a DiffServ testbed being developed at the University of Greenwich for evaluating various design options relating to the provision of quality of service over the Internet. The present implementation includes: (a) a packet classifier which assigns incoming packets to different queues based on the ToS field in the IP header; (b) packet queues with finite buffers; (c) a scheduler which implements the WFQ algorithm. Preliminary results include queuing delays and loss probabilities for different packet arrival rates, service weights and buffer size.