H.323/VoIP QoS

Joon Maeng Joon_Maeng at VTEL.COM
Wed Mar 3 11:40:21 EST 1999


I have a question regarding multipoint conferences in H.323.

In the H.323 standard, it seems as if the "Conference Invite" functionality
(see requires that calling party (Endpoint 1) already before making
the call set-up to Endpoint 2 (E2) must have decided that E2 shall be
brought into the conference as a new member. So it is not possible for E1 to
make an enquiry (consultation) call to see if E2 has the time to
participate, has the required competence or whatever the criterion for
participation might be.

But, when I look at the Draft new recommendation H.450.8 "Conference out of
Consultation Supplementary Service for H.323 (SS-CoC)" (February 8, 1999),
it seems to have what I am looking for.

According to this recommendation, it is possible to make a call, put the
called (or calling of course) party on hold, make a consultation call and at
that moment (after talking to the E2 party) decide to create a conference.

But how do I do if I want to expand this to yet another party in the same
way? According to H.450.8 (7.4.1), I shall use the H.323 "conference

That would mean that I have to use different principles when I go from a
2-party to a 3-party call, than when I go from an N-party to an (N+1)-party
call. Does it have to be like that? I really think that it would be nice if
the H.450.8 recommendation can be expanded to cover also cases when the held
call is a conference. Currently, it only covers the case where the held call
is to to a remote user.

I would be glad to get your opinion regarding this.

Best regards

Hans Andersson

        Hans Andersson
        System Design
        GSM Systems                                                     Tel:
+46 8 757 22 38
        Ericsson Radio Systems AB                               Fax: +46 8
404 95 30
        F $B3SSH (Batan 6, Kista                                                Mob:
+46 70 533 91 12
        S-164 80 STOCKHOLM
Hans.E.Andersson at era.ericsson.se


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