APC-1285 - Use of H.245 in Supplementary Services - posted

[Pete Cordell]

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