SCTP Subflows for Survivable FCS Applications
Abstract:
The Stream Control Transmission Protocol (SCTP), a general-purpose transport layer protocol standardized by the IETF, has been a promising candidate to join UDP and TCP as a core protocol. The new SCTP features such as multi-homing, multi-streaming, and enhanced security can significantly improve the performance of FCS applications. Multi-streaming provides an aggregation mechanism in an SCTP association to accommodate heterogeneous objects, which belong to the same application but may require different type of QoS from the network. However, the current SCTP specification lacks an internal mechanism to support the preferential treatment among its streams. We introduce the concept of subflow and propose to modify the current SCTP such that the streams are grouped into several subflows according to their required QoS. It is also proposed that each subflow should implement its own congestion control to prevent the so-called false sharing. To compare the throughput differences, analytic models have been derived for the current SCTP and for the subflow-capable SCTP with different congestion control mechanisms. Simulations with ns-2 have been used to qualitatively demonstrate the throughput differences of these designs in a simplified diff-serv network. The analytical models are confirmed to accurately reflect the SCTP behavior. The simulation also shows that our proposed solution is able to efficiently support QoS among the SCTP streams.
