SIGTRAN

SIGTRAN is the name, derived from signaling transport, of the former Internet Engineering Task Force (IETF) working group that produced specifications for a family of protocols that provide reliable datagram service and user layer adaptations for Signaling System 7 (SS7) and ISDN . The SIGTRAN protocols are an extension of the SS7 protocol family. It supports the same application and call management paradigms as SS7 but uses an (IP) transport called (SCTP), instead of TCP or UDP. Indeed, the most significant protocol defined by the SIGTRAN group is SCTP, which is used to carry PSTN signaling over IP.

The SIGTRAN group was significantly influenced by telecommunications engineers intent on using the new protocols for adapting VoIP networks to the PSTN with special regard to signaling applications. Recently, SCTP is finding applications beyond its original purpose wherever reliable datagram service is desired.

SIGTRAN has been published in RFC 2719, under the title Framework Architecture for Signaling Transport. RFC 2719 also defines the concept of a signaling gateway (SG), which converts Common Channel Signaling (CCS) messages from SS7 to SIGTRAN. Implemented in a variety of network elements including softswitches, the SG function can provide significant value to existing common channel signaling networks, leveraging investments associated with SS7 and delivering the cost/performance values associated with IP transport.

The SIGTRAN family of protocols includes:

The provides the for SIGTRAN user adaptation layer messages across an IP network. It is described in RFC 3873, RFC 4166 and RFC 4960.

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