URQ ambiguity

[Chris Wayman Purvis]

Paul,

I agree that an endpoint shall not reject its gatekeeper's URQ.
However, I disagree with you on the other part of this.  If the gatekeeper
sends a URQ containing no aliases this should be taken as complete
unregistration.

Scenario: Gatekeeper is preconfigured with all endpoints it will allow to
register with it, but users have free choice of what (and how many) aliases to
use.  This preconfiguration information is retained over power-cycle, but
current registrations are not.  If the gatekeeper loses power gracelessly, on
reboot it may send URQs to all endpoints it permits to register with it, to
ensure that all endpoints know they need to reregister.

Regards,
Chris

---------------------------
Paul wrote...

Folks,

In reviewing some H.323v4 text, I noticed some ambiguity.  Refer to section
7.2.2, it says:

    A Gatekeeper may cancel the registration of an endpoint by sending an
Unregister Request (URQ)
    message to the endpoint. The endpoint shall respond with an Unregister
Confirmation (UCF) message.
    The endpoint shall attempt to re-register with a Gatekeeper prior to
initiating any calls. This may require
    the endpoint to register with a new Gatekeeper.
    If the Gatekeeper sends a URQ message containing a list of alias addresses,
the endpoint shall
    assume that only those alias addresses are unregistered if it chooses to
accept the request. If the
    Gatekeeper sends a URQ message that does not contain any alias addresses,
the endpoint shall
    assume that all alias addresses, if any, are unregistered if it chooses to
accept the request.


I see two troublesome parts to this text.  The text that says "if it chooses to
accept the request" is one.  I don't
believe that an endpoint has a choice-- it shall always reply with UCF as
stated in the first paragraph.  The last
sentence of the second paragraph makes no sense at all.  If a Gatekeeper sends
a URQ with no aliases, that is
already understood by all endpoints that the endpoint is no longer registered--
it cannot simply imply that all
aliases are unregistered, but not the endpoint itself.

I would like to propose that we delete all of this text from H.323:

    if it chooses to accept the request. If the Gatekeeper sends a URQ message
that does not contain any
    alias addresses, the endpoint shall assume that all alias addresses, if
any, are unregistered if it
    chooses to accept the request

Any opinions?  If we get agreement, I'll bring such a proposal to the next
meeting.

Paul



--
Dr Chris Purvis -- Development Manager
ISDN Communications Ltd, The Stable Block, Ronans, Chavey Down Road
Winkfield Row, Berkshire.  RG42 6LY  ENGLAND
Phone: +44 1344 899 007
Fax:   +44 1344 899 001

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