Third party registration/group registration

Chris Wayman Purvis cwp at isdn-comms.co.uk
Mon Dec 4 08:44:03 EST 2000


Paul,

> I'll be happy to present anything.  Can't say that I will defend anything,
> but I'll present it :-)
Past experience shows that on complex issues this simply is not sufficient -
there will be too many people who don't understand, hence fear, hence (if it
ever comes to a vote) oppose any proposal in either camp.  So, realistically,
nothing will result.
Not that I don't understand that you have plenty else to do at these meetings!

> I missed much of the discussion, so if you wouldn't mind, will you write an
> e-mail me summarizing the two opposing opinions?
There are a three questions I can identify in this discussion.  Note that the
answers I give with initials CWP by them are mine, PL are Paul Long's views as
I understand them, CA are Charles Agboh's views as I understand them.  If I
have misunderstood the views of either of these people I apologise and would be
obliged if they would clarify their positions.  I am not intending to
misrepresent anybody, but I may have inadvertently done so!

Q1. Is a device permitted to call itself H.323 if it does not support RAS (or
can be configured not to use RAS)?
A1a (CWP). No, on the grounds that certain RAS messages are mandatory for
devices to support (H.225.0 section 7.7)
A1b (CA, PL). Yes, on the grounds that gatekeepers are an optional part of an
H.323 system.

Assume RAS is being supported in a particular "system" (without prejudging the
answer to Q1), and we come to the other question:
Q2. If an endpoint has attempted gatekeeper discover and/or registration, and
been rejected (GRJ or RRJ) by all gatekeepers it has found (this being at least
one gatekeeper), is the endpoint permitted to make and receive H.323 calls?
A2a (CWP). No, on the grounds that there is a gatekeeper in control of this
system, and it has denied access.  Also on grounds of common sense (ARJ makes
no sense if an endpoint may deregister and then make the call it's been
refused).
A2b (PL). Yes, presumably on grounds of restrictiveness.

Q3. Should third-party registration be standardised?
A3a (CA). Yes.
A3b (CWP). Possibly, but before this can be answered a LOT of clarification is
required on what is meant by the term "third-party".

Regards,
Chris
> ----- Original Message -----
> From: "Chris Wayman Purvis" <cwp at isdn-comms.co.uk>
> To: <plong at ipdialog.com>; <ITU-SG16 at mailbag.cps.intel.com>; "Paul Jones"
> <paul.jones at ties.itu.ch>; <rkbowen at cisco.com>
> Sent: Friday, December 01, 2000 11:57 AM
> Subject: Re: Third party registration/group registration
> 
> > All,
> >
> > I think on the matter of whether the standards permit H.323 entities to
> > continue to operate unregistered in an environment where there is a
> gatekeeper,
> > in two cases:
> > 1. They have discovered the gatekeeper, but have been rejected by either
> GRJ or
> > RRJ.
> > 2. No attempt has been made to discover a gatekeeper.
> >
> > I have a view.  Paul Long has a view.  I have a different view.  These
> differ.
> > I believe, however, that whichever view prevails, one must, and this must
> be
> > through the standards themselves.  Common usage can not decide this, as
> it's a
> > question of whether something is permitted by the standard.  I could draw
> up a
> > very quick proposal (<= 1/2 page) for the next ITU meeting, but I will not
> be
> > able to come and present it.   To help the experts at the meeting to come
> to
> > the right decision, however, opposing proposals probably ought to be
> presented
> > properly by their authors, giving the two viewpoints.  Any volunteers
> (Rick?
> > Paul J?  As editors of the relevant standards?)?
> >
> > Regards,
> > Chris
> >
> > Paul Long wrote:
> > >
> > > Chris,
> > >
> > > Re Re Q2: Yes, I agree with A2c, but I see no point in wasting _any_
> > > bandwidth for RAS on a system that does not contain a gatekeeper.
> > >
> > > Re Re Q3: I think we understand each other and that we'll just have to
> agree
> > > to disagree on this. It's up to the implementation and ultimately the
> market
> > > to decide whether the user may disable RAS.
> > >
> > > Re Re Q4: Correct, if something behaves "as if" it were compliant then I
> > > suppose it is, well... compliant. :-) No change is necessary to the
> > > Recommendations.
> > >
> > > Paul Long
> > > ipDialog, Inc.
> > >
> > > -----Original Message-----
> > > From: Chris Wayman Purvis [mailto:cwp at ISDN-COMMS.CO.UK]
> > > Sent: Friday, December 01, 2000 8:41 AM
> > > To: ITU-SG16 at MAILBAG.INTEL.COM
> > > Subject: Re: Third party registration/group registration
> > >
> > > Paul,
> > >
> > > > Gettin' closer.
> > > I think (and hope!) so!
> > >
> > > > Re Q2: I simply can't justify making the user wait several seconds for
> a
> > > > discovery that will always fail in a system without a gatekeeper
> before he
> > > > or she can place or answer each and every call. Can you? Therefore,
> the
> > > user
> > > > should be able to turn off RAS.
> > > So you'll agree on answer c then?
> > > What about regular reattempts to find a gatekeeper (excluding my
> suggestion
> > > of
> > > when a call is attempted).
> > >
> > > > Re Q3: I agree with you, except that with some endpoints the user may
> then
> > > > turn off RAS and place or answer calls without RAS. Note that the
> typical
> > > > user will most likely not do this, since at least placing a call
> without a
> > > > gatekeeper would require more knowledge than the average user
> posseses,
> > > > e.g., the IP address of the called party.
> > > This is where I disagree, on the grounds that if we allow calls in
> systems
> > > with
> > > gatekeepers from endpoints that are not registered, we may as well throw
> > > away
> > > the gatekeeper altogether (or at least call it a proxy and start
> speaking
> > > SIP).
> > >
> > > > Re Q4: Maybe he has decomposed his endpoint. In the C Standard, there
> is
> > > > something called the "as if" rule. Applying it here, if the system
> > > > experiences consistent behavior from a possibly decomposed entity that
> is
> > > > acting "as if" it were a corporate entity, it is compliant IMO. Who
> cares
> > > > where messages originate as long as the effect is the same? In a
> different
> > > > way, the "as if" rule is what allows routing gatekeepers to do what
> they
> > > > do--they can fiddle with messages streams all they want as long as
> they
> > > > maintain consistency "as if" the message streams were originating from
> a
> > > > compliant endpoint.
> > > Surely if the "as if" rule applies there can be no requirement for any
> > > changes
> > > to the standard - otherwise it isn't "as if"!
> > > I grant the possibility of the decomposed endpoint, although I don't
> > > personally
> > > understand why anyone would want to, as the communication between the
> > > decomposed parts would be at least as complicated as RAS itself.
> > >
> > > > Note that when I say, "user," I mean either the actual user of the
> > > endpoint
> > > > or possibly an administrator of the system. I think it's perfectly
> > > > reasonable to make the use of RAS an administrated setting.
> > >
> > > Agreed.
> > >
> > > Regards,
> > > Chris
> > >
> > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > > For help on this mail list, send "HELP ITU-SG16" in a message to
> > > listserv at mailbag.intel.com
> >
> > --
> > 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
> >

-- 
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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