# Glossary: SIGTRAN

## SIGTRAN

SIGTRAN refers to the ability to provide [SS7](https://telcobridges.gitbook.io/prosbc-documentation/glossary/glossary-ss7) and [ISDN](https://prosbcdocs.telcobridges.com/hidden-pages/glossary-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 <a href="#telcobridges-and-sigtran" id="telcobridges-and-sigtran"></a>

TelcoBridges' SIGTRAN implementation provides support for [SCTP](https://docs.telcobridges.com/wiki/SCTP), [M2PA](https://docs.telcobridges.com/wiki/M2PA), [M2UA](https://docs.telcobridges.com/wiki/M2UA), [M2PA](https://docs.telcobridges.com/wiki/M2PA), [M3UA](https://docs.telcobridges.com/wiki/M3UA) and [IUA](https://docs.telcobridges.com/wiki/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](https://docs.telcobridges.com/wiki/MTP3_Layer) 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/Tmedia) | 64 in\&out         | 512 (64/Tmedia) | 1024 (64/Tmedia) | 64         | 60                   |

Standard references:

* SCTP

RFC 4960, September 2007

* M3UA

RFC 4666, IETFM3UA, 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 2007ETSI TS 102 332 V1.1.1 ISDN Q.921 User Adaptation Layer

#### References <a href="#references" id="references"></a>

* [Wikipedia article](http://en.wikipedia.org/wiki/SIGTRAN)
* [Introduction to SIGTRAN, by Jim Darroch](https://www.slideshare.net/krsgowri/sigtran-13102919)
* [Pricing model (TelcoBridges)](https://docs.telcobridges.com/wiki/SIGTRAN_pricing_model_2011)


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