An Adaptive SCTP Congestion Control Scheme Based on Receiver Available Bandwidth Estimation

Streaming control transmission protocol (SCTP) is one kind of new generation transport layer protocol, is a little modification form TCP. Like TCP, the congestion control mechanism of current SCTP relies on packet loss as an indicator of network congestion. When congestion been detected the sender will reduce congestion window size to half to avoid congestion. In wire/wireless network environment, the packet losses are not all ways because of congestion. If SCTP reduces the congestion window inappropriately in an error prone wireless network, it may not use the network resource efficiently. For the purpose to improve the performance of SCTP congestion control, especially in an error prone wireless network, we propose a new enhancement SCTP called RSCTP (Receiver Bandwidth Estimation SCTP) based on receiver-side available bandwidth estimation. RSCTP relies on bandwidth estimation to discriminate wireless loss from congestion loss over error prone wireless link, it also reduces congestion window and slow start threshold appropriately. In multihoming mode, using chunk loss rate estimation, RSCTP can switch path actively over the high loss rate environment. We use NS2 to implement RSCTP and the simulation results reveal that our scheme improves performance efficiently over error prone wireless network in evidence.