SIP-T

The SIP Reason header field is defined to carry ISUP (ISDN User Part) cause values as well as SIP response codes. Some services in SIP networks may need to know the ISUP location where the call was released in the PSTN (Public Switched Telephone Network) to correctly interpret the reason of release. This document updates RFC 3326 by adding a location parameter for this purpose.

This document describes a way to map Integrated Services Digital Network User Part (ISUP) overlap signalling to Session Initiation Protocol (SIP). This mechanism might be implemented when using SIP in an environment where part of the call involves interworking with the Public Switched Telephone Network (PSTN). [STANDARDS-TRACK]

This document describes a way to perform the mapping between two

signaling protocols: the Session Initiation Protocol (SIP) and the

ISDN User Part (ISUP) of SS7. This mechanism might be implemented

when using SIP in an environment where part of the call involves

interworking with the Public Switched Telephone Network (PSTN).

The popularity of gateways that interwork between the PSTN (Public

Switched Telephone Network) and SIP networks has motivated the

publication of a set ofcommon practices that can assure consistent

behavior across implementations. This document taxonomizes the uses

of PSTN-SIP gateways, provides uses cases, and identifies mechanisms

necessary for interworking. The mechanisms detail how SIP provides

for both 'encapsulation' (carriage of PSTN signaling across a SIP

network) and 'translation' (protocol mapping).