Performance of SCTP-controlled Failovers in M3UA-based SIGTRAN Networks

摘要

There are some large economic, operational, and, to some extent, technical incentives to replace the traditional telecom network with IP. However, such a large transition will not happen overnight - maybe never. Meanwhile, IP-based and traditional TDM-based telephony will have to co-exist. To address this situation, the IETF SIGTRAN working group has developed an architecture for transportation of Signaling System No. 7 (SS7) traffic over IP. Still, it remains to be shown that the introduction of the SIGTRAN architecture will not significantly deteriorate the performance of SS7. To this end, this paper evaluates the failover performance in SIGTRAN networks. Specifically, the paper evaluates the performance of SCTP-controlled failovers in M3UA-based SIGTRAN networks. The paper suggests that in order to obtain a failover performance with SCTP comparable to that obtained in traditional TDM-based SS7 systems, SCTP has to abandon many of the configuration recommendations of RFC 2960 and become much more aggressive in its failover behavior. Furthermore, the paper suggests that the SCTP parameter Path. Max. Retrans has a major impact on the SCTP failover performance. Our evaluation also indicates that for those path propagation delays envisioned in future SIGTRAN networks, the impact of the path propagation delay on the failover performance is marginal.