Fair bandwidth allocation among LSPs for AF class accommodating TCP and UDP traffic in a Diffserv-capable MPLS network

To resolve the issue of excess AF bandwidth unfairly allocated by RIO (RED with IN/OUT) among LSPs with AF-class TCP traffic in a Diffserv-capable MPLS network, we previously proposed a technique, called weighted fair RIO (WF-RIO) (K. Tsunekawa, 2004), to allocate excess AF bandwidth among LSPs in proportion to the minimum guaranteed AF bandwidth. In the case of TCP traffic and UDP traffic coexisting in an AF class, WF-RIO does not effectively provide the fair bandwidth allocation, because the behavior of UDP traffic is different from that of TCP traffic. To solve this problem, we examine a scheme, which includes marking at the MPLS ingress router and queuing at the MPLS core router, for implementing a policy in which excess AF bandwidth should be allocated to the TCP traffic and UDP traffic in the AF class of each LSP in proportion to the quality demand for each kind of traffic. To demonstrate the effectiveness of the proposed scheme, we evaluate it by computer simulation.