Guaranteed QoS for TCP flows in ATM-based DiffServ Networks"
ECUMN '2000, Colmar, France
We investigate the QoS which a single user observes in a DiffServ network which
is based on ATM. We show that TCP flows can experience performance degradation
compared to UDP flows, even if the network is well tuned. The reason for this
behavior is the TCP congestion control mechanism. Individual TCP flows cannot
benefit from guarantees provided by ATM on the aggregate level. We introduce
a new scheme called Fair Queuing and Selective Marking (FQSM) which overcomes
this problem. It is located at the network edges and requires no changes to
an existing ATM network. Simulations show good performance and allow to give
QoS guarantees for TCP connections.