A Scheme of Primary Path Switching for Mobile Terminals using SCTP Handover

Stream Control Transmission Protocol (SCTP) is a new transport layer protocol for end-to-end data transport. SCTP can be used to support soft handover for mobile terminal with the help of the SCTP multi-homing feature. For SCTP handover, a mobile terminal is required to switch the primary path to one of the promising alternative paths. This paper proposes a new scheme of the primary path switching for SCTP handover, which is based on the absolute gap and relative ratio of the Round Trip Times (RTTs) measured for the primary and alternative paths. For experiments, we consider the ping-pong movement pattern, which a mobile terminal moves around the two different IP networks. From the experiments we see that a conservative scheme is preferred for primary switching in the networks with relatively small absolute gaps of RTTs, whereas an aggressive scheme needs to be considered in the cases with large absolute RTT gaps. Key-Words: SCTP, Handover, Primary Path Switching, Ping-pong Movement Pattern, Round Trip Time