A TCP-friendly traffic marker for IP differentiated services

The differentiated services architecture allows the provision of "better-than-best-effort" services in the Internet. However the performance of legacy TCP applications over differentiated services is still influenced by bursty packet loss behavior. This paper proposes the use of TCP-friendly building blocks in the Diffserv architecture, and in particular, a TCP-friendly traffic marker to enhance TCP performance over assured service. We present the marker design and resulting performance improvements in terms of improved predictability of service, reduced provisioning requirements, better fairness and fewer TCP timeouts. Though the marker improves assured service performance predictability compared to a simple token bucket marker, the performance is still dependent to some extent on TCP dynamics.