Summary

Recommendation ITU-T Q.1912.5 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. It includes assured early dialogue, end-to-end support for ISDN user equipment, support for number portability and support for the interworking of supplementary services.

Corrigendum 1 revises the text of clauses IV.3.2.1 and IV.3.2.2 of Appendix IV, Echo canceller scenarios between SIP and ISUP.