Registration of the contributions

Sakae OKUBO okubo at
Fri Nov 6 23:02:27 EST 1998


The second gateway decomposition audio call was held Tuesday 11/3 from 11AM
to 1PM EST.  The following companies were represented on the call AT&T,
Dialogic, Ascend, 3COM, Telogy Networks, Bellcore, Lucent, RADVision,
Nortel, PakNetx, BT, VideoServer, and others.

Tom Taylor presented the TIPHON document 10td101r1 that discussed
requirements for Interface A of the gateway decomposition model.  The
following issues were discussed.

-       Interface A will be limited to media control only, but events such
as DTMF tones or call authorization occur can occur which are relevant to
call signaling.  A position was stated that when call signaling information
is carried in-band form the SCN side, the media gateway component will need
to recognize these events and report them to the control gateway component.
It will be the control component of the gateway that will act on this
information.  After some time the discussions were halted and can revisited
in Torino.
-       Management of media gateway resources was discussed.  It was pointed
out that similar resource management debate for revision 2.0 was a lengthy
late night session that resulted in a very limited solution to the problem.
The scope of our current discussion is to accommodate voice which makes the
resource management problem much more straightforward.  A concern was raised
that agreeing to a short sighted voice solution that cannot be extended in
the future is a bad thing and needs to be avoided.
-       The load balancing and hot stand-by capabilities common among of SS7
equipment was raised was raised as a requirement for the gateway.  There was
considerable discussion regarding the definition of these terms and the
requirements for such functionality centering around whether this is a
problem to solve with protocol or implementation.
-       A discussion regarding the applicability of using IETFs MGCP work
for interface A was raised.  The MGCP work was considered premature and not
ready for use by the ITU-T.  Considerable discussion regarding the
desirability to leverage the IETFs work occurred and many agreed that the
ITU and IETF should make every effort to arrive at complementary solutions
to this problem.

The discussion shifted to the B, C and D interface and Mr Sijben presented
another TIPHON document 10td91.  This document that presented the merits of
mapping H.225 messages to ISUP messages.  If further stated that H.225
facility UUIEs could be used to transport ISUP (or QSIG) messages, that are
not applicable to H.225 messages, through the H.323 network.  A proposal for
abstracting the ISUP and H.225 and creating an abstract protocol was raised.
Another proposals  for using UDP to tunnel SS7 through the H.323 network was
were suggested but due to time restraints the latter two options were not
discussed in much detail.  The proponents of these techniques agreed to
submit these as APC to the November meeting in Torino.

In closing there was some discussion about trying to hold a third call prior
to the Torino meeting, but the group decided there was  not sufficient time
to hold such a meeting.

Best Regards,
Bryan Hill

Bryan Hill
VideoServer Inc.
(781) 505-2159
bhill at <mailto:bhill at>

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