SIGTRAN is a protocol suite intended to transport signaling protocols over IP, and are an extension of the SS7 protocol family. It supports the same application and call management paradigms as SS7 but uses an Internet Protocol (IP) transport called Stream Control Transmission Protocol (SCTP). In applications where high availability is not required, TCP may replace SCTP.
A typical use for SIGTRAN is in Signaling Gateways that allow voice over IP networks to interwork with traditional telephone networks using circuit switching and SS7. The gateway receives the signaling messages coming from the SS7 network and forwards them on the IP side with SIGTRAN.