An Easy way to Reduce SCTP Failover Times

• To enable interoperability between the public switched telephone network and IP, the IETF SIGTRAN working group has developed an architecture for the transportation of SS7 signaling traffic over IP. The architecture is based on a new transport protocol, the Stream Control Transmission Protocol (SCTP), that is designed to meet SS7 requirements. However, recent work suggests that the SCTP failover mechanism has difficulties complying with the SS7 requirements of ITU-T. To this end, this paper suggests using a modified retransmission timeout strategy which involves using a relaxed backoff factor of less than 2, the standard value specified in RFC 2960. Through simulations, it is shown that significant improvements in failover time, and thus in increased permissible network delays, could be obtained with this backoff strategy in well-dimensioned and controlled network environments. However, the simulations also stress the importance of running signaling traffic over managed IP networks. In the simulations where the signaling traffic competed with uncontrolled cross traffic, none of the studied backoff factors made SCTP compliant with ITU-T.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Telekommunikation (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Telecommunications (hsv//eng)

Keyword

SCTP

failover

SIGTRAN

retransmission

timeout

backoff

Computer Science

Datavetenskap

Publication and Content Type

ref (subject category)

kon (subject category)