RTOmin as a balancing parameter between fast retransmissions and timeouts within stream control transmission protocol (SCTP)

Abstract

The Stream Control Transmission Protocol (SCTP) is a transport layer protocol introduced to complement the well known User Datagram Protocol (UDP) and the Transmission Control Protocol (TCP). The current implementation of SCTP heavily leverages some existing mature techniques from TCP. This paper studies the effect that RTOmin (retransmission timeout minimum) has on the selective acknowledgement (SACK), fast retransmission, and timeout mechanisms. We show that there are optimization opportunities in the manipulation of RTOmin while not significantly affecting timeout values and number of fast retransmissions. We demonstrate that RTOmin plays a balancing role in the trigger of timeouts and fast retransmissions and conclude that a dynamically set RTOmin would yield significant time-to-complete (throughput) improvements for SCTP based applications.