Packet Loss Recovery of Signaling Traffic in SCTP
Per Hurtig and Anna Brunstrom
International Symposium on Performance Evaluation of Computer and Telecommunication Systems (SPECTS 2007)
San Diego, California (USA), July 16-18, 2007
SPECTS_Summary
The Stream Control Transmission Protocol (SCTP) was developed to be a viable solution for transportation of signaling traffic within IP-based networks. Signaling traffic is different from ordinary bulk traffic in many ways. One example of this, is that the requirements of timely delivery usually are much stricter. However, the loss recovery mechanisms in SCTP are not fully optimized to these requirements. For instance, if packet loss occurs when the amount of outstanding data is small, a SCTP sender might be forced to rely on lengthy timeouts for loss recovery. This paper presents a number of proposals that try to solve this particular problem, with focus on the Early Retransmit mechanism. We propose a modification to Early Retransmit, to adapt it to signaling scenarios, and evaluate its performance experimentally. The results show that the modified Early Retransmit mechanism is able to provide significant reductions in loss recovery time. In some cases, the time needed to recover from packet loss was reduced with as much as 67%.