scope:

The present document is to investigate the interoperability of H.323 and B-ISDN signalling environments with a view to identifying possible standardization activities in this area. The following aspects of interoperability are investigated:

• the interworking of H.323 and B-ISDN environments, both separated and combined, via a gateway;
• the connection of remote H.323 environments via B-ISDN;
• the use of H.323 annex C (H.323 on ATM), including the co-existence of H.323 annex C and B-ISDN signalling in the same network and possible future enhancement of annex C;
• the application of the B-ISDN separated call control protocol to gatekeeper-to-gatekeeper communication;
• the impact of H.323 on future mobility protocols.

For each of the above, due consideration is given to the following: addressing impact (including use of IP addressing); conferencing models; T.120 data impact; basic call procedures; generic functional procedures (GFP) and supplementary services; end-to-end resource and session level protocols.

Possible future standardization activities resulting from the present document will include H.323 work items as well as B-ISDN signalling work items.