Dear All,

APC-1285 - Use of H.245 in Supplementary Services - has been posted to the FTP site. A number of details have been changed since earlier drafts, but the principle is the same. The tone is also changed to encompass third party call control in general rather than just supplementary services. The abstract is as follows:

A major issue in H.323 is that if a remote party does not support a particular supplementary service that you wish to use then you will not be able to use it, even if you yourself support it. This is particularly important when a remote endpoint calls into a managed signalling environment where supplementary services are supported. Currently, if the endpoint that is calling in does not support supplementary services, then it will be impossible to keep track of a call while transferring the endpoint to another endpoint within the environment. What is required is for the gatekeeper to perform some form of third party call control. This is an fundamental element of call control and needs to be supported in H.323. This proposal suggests making use of H.245 empty capability sets to implement this. The proposal also allows for the signalling of remote hold, which is useful in its own right.

Regards,

Pete ================================= Pete Cordell BT Labs E-Mail: pete.cordell@bt-sys.bt.co.uk Tel: +44 1473 646436 Fax: +44 1473 643791 =================================