[Robustness] Conference call - final reminder and more agenda ite ms -- Tuesday, November 16 11AM EST USA
Maureen.Stillman at NOKIA.COM
Mon Nov 15 15:00:55 EST 1999
This is a final reminder that we will be having the first teleconference on
robustness sponsored by Nokia on Tuesday, November 16 at 11AM EST USA.
The phone number to call is:
613-688-2795 and the access code is 1097#. You must enter the pound key
after the access code.
The tentative agenda is:
Definitions of Terms for robustness
Items that can be settled in the short term
Additional agenda items from the mailing list:
They are topics we should discuss during the phone call or decide to defer.
I took most of this text directly from your e-mail messages....
Summary of Agenda Items from the mailing list:
1) contribution D.225 - "Framework for Reliable H.323
Gatekeeper Architectures" How will this contribution be added and referenced
in the "terms of reference" Red Bank document TD-028?
2) Further discussion of the proposal in Red Bank to strike the
text in the current version that allows for the closure of the call
signaling channel while a call is still in progress.
3) Recovery from GK crash
4) The more difficult problem is that upon TCP channel failure,
the TPKT connection gets out of synch. It means that the application layer
doesn't know automatically what part of information got lost. In this case,
in order to synchronize H.323 Call state between the two sides, application
level handshake must be introduced. This is also definitely a job for our
5) Another issue we have at hand is that of "what is a call
signaling channel?" There used to be a one to one mapping between TCP
connections and call signaling channels. This is not the case any longer--
one may have multiple calls over the same call signaling channel and one may
not even use TCP. Making this distinction will be important for the
robustness work being started, as the "logical" connection (the call
signaling channel) and the "physical" connection (the TCP or UDP connection)
must be referred to independently. (I'm quite open to new terms for
here...). It is important to recognize whether an endpoint has closed the
call signaling channel (as we understand it today) or if the physical
connection has failed. Since we do not signal that we are going to close
the call signaling channel today-- we just close the socket-- it makes this
problem more difficult.
6) Actually, the SCTP transport protocol defined by Sigtran is
specifically designed to address the path level robustness. It is designed
to support multiple NIC cards (a.k.a. multi-homed nodes) and provide
transparent interface and path failure detection and recovery.
7) think that Sigtran could be used to provide the GK "switch
over" to a hot standby GK from the IP layer point of view.
Conference Call Participants (so far): all are welcome to join in!
Rich Bowen rkbowen at cisco.com
Roy Radhika rrroy at att.com
Orit Levin orit at radvision.com
Dave Walker dave_walker at Mitel.com
Terry Anderson tla at lucent.com
Kumar, Vineet vineet.kumar at intel.com
Asaf Steifeld AsafS at radware.co.il
Michael Corrigan Michael_Corrigan at mw.3com.com
Robert Callaghan Robert.Callaghan at siemenscom.com
Glen Freundlich ggf at lucent.com
Boaz Michaely Boaz_Michaely at vocaltec.com
Jean-philippe Caradec caradec at piano.grenoble.hp.com
Talk to you Tuesday....
Member of Scientific Staff Voice: (607)273-0724 x62
Nokia IP Telephony Fax: (607)275-3610
127 W. State Street Mobile: (607)227-2933
Ithaca, NY 14850
e-mail: maureen.stillman at nokia.com
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