(
SIGnaling
TRANsport) An IP telephony protocol from the IETF that is used to transfer SS7 signals over IP networks. The telco switch sends SS7 signals to a signaling gateway (SG) that converts them into SIGTRAN packets, which travel over IP to the next signaling gateway or to a softswitch if the destination is not another PSTN. SIGTRAN uses the Stream Control Transmission Protocol (SCTP) for reliable transport. See
IP telephony and
SCTP.