The present document provides the ETSI endorsement of the ITU-T Recommendation Q.1912.5 [1].
ITU-T Recommendation Q.1912.5 [1] defines the signalling interworking between the Bearer Independent Call Control (BICC) or ISDN User Part (ISUP) protocols and SIP in order to support services that can be commonly supported by BICC or ISUP and SIP-based network domains.
The present document is applicable to ETSI PSTN/ISDN networks interworking with networks based on an IETF based SIP/SDP profile as defined in annex C of ITU-T Recommendation Q.1912.5 [1].
In the case where an IMS-based network interworks with the PSTN/ISDN, then the ETSI endorsement of 3GPP TS 29.163, in either ETSI TS 129 163 [29] and ETSI ES 283 027 as appropriate to the applicability of each document, takes precedence.
Formats, codes and procedures marked for national use or as network option are included for informative purposes for the international interface specification. If these items so marked are supported within a national network and operator's network, then it is proposed that they are supported in this manner.