SIGTRAN refers to the ability to provide SS7 and ISDN signaling over an IP network.

SIGTRAN is the name given to an Internet Engineering Task Force (IETF) working group that produces specifications for a family of protocols that provide reliable datagram service and user layer adaptations for SS7 and ISDN communications protocols. SIGTRAN is an extension of the SS7 protocol family. It supports the same application and call management paradigms as SS7 but uses an IP transport called Stream Control Transmission Protocol (SCTP) as its underlying transport vehicle. Indeed, the most significant protocol defined by the SIGTRAN group was SCTP, which is used to carry PSTN signaling over IP.

TelcoBridges and SIGTRAN

TelcoBridges provides support for SIGTRAN starting from Toolpack v2.4. TelcoBridges' SIGTRAN implementation provides support for SCTP, M2UA, M2PA, M3UA and IUA.

Among the features of TelcoBridges' SIGTRAN implementation are the following:

  • M2PA with 64 links (termination)
  • M2UA in SG and ASP mode (relay)
  • M3UA in SG, ASP and IPSP mode (relay)
  • M3UA with load distribution features similar to the MTP3 stack (termination)

Maximum Capacity

Model SCTP links SCTP streams/links M2PA links M2UA links M3UA links M3UA routing context
TMG800 64 64 in&out 64 64 64 60
TMG3200 64 64 in&out 64 64 64 60
TMG7800 1024
64 in&out 512
64 60

Standard references:

  • SCTP
RFC 4960, September 2007
  • M3UA
RFC 4666, IETF
M3UA, Implementation Guide, IETF, 2002
  • M2UA
SS7 MTP2-User Adaptation Layer, RFC 3331, IETF
  • M2PA
RFC 4165, IETF
  • IUA
IETF RFC 5133 ISDN Q.921 User Adaptation Layer, December 2007
ETSI TS 102 332 V1.1.1 ISDN Q.921 User Adaptation Layer