Improving Throughput in SCTP via Dynamic Optimization of Retransmission Bounds

Abstract

The Stream Control Transmission Proto-
col (SCTP) is a relatively new transport protocol. It
has several underlying mechanisms that are similar to
the Transmission Control Protocol (TCP), as well as
several improvements that are important in certain
classes of applications. The timeout scheme of SCTP,
however, is almost identical to that used in TCP.
With the dynamics of today’s Internet, that timeout
scheme may be too passive. This paper presents an al-
gorithm which dynamically adjusts the overall context
of the retransmission timeout process without chang-
ing the fundamental retransmission mechanisms. This
approach manages the impact of fast retransmissions
and timeouts to significantly improve the throughput
of SCTP applications. The algorithm has been im-
plemented and tested in real network environments.
Experimental results show that the algorithm avoids
spurious retransmissions and provides better through-
put by intelligently managing RTO boundaries and
allowing conventional timeout schemes to participate
more actively in the retransmission process.