Third party registration/group registration
plong at PACKETIZER.COM
Fri Dec 1 08:30:58 EST 2000
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.
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.
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
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.
From: Chris Wayman Purvis [mailto:cwp at ISDN-COMMS.CO.UK]
Sent: Friday, December 01, 2000 3:46 AM
To: ITU-SG16 at MAILBAG.INTEL.COM
Subject: Re: Third party registration/group registration
I think we're starting to converge. Let's separate this out now, into
Q1. Are endpoint devices (in which term I include gateways etc throughout
mail) required to implement RAS?
A1. Yes (agreed between you and me, disagreed by Charles).
Q2. How does an endpoint device know whether or not a gatekeeper is present
the system, and hence whether or not to use RAS?
A2a (Your position as I understand it.) Configuration, discovery on
give up if you don't find anything then.
A2b (My suggestion) Configuration, discovery on startup, retry at some
reasonable frequency (hourly?), take the three seconds to attempt gatekeeper
discovery when someone makes a call to or from the endpoint in question.
A2c (What we'll probably end up agreeing!) Implementation decision.
Q3. What should an endpoint do if it attempts to register with all
gatekeepers, where there is at least one gatekeeper in the system, and fails
A3a (My position) Shut itself down.
A3b (Anybody elses) ???
Q4. Is Charles's actual application, where one entity is registering and
presumably (although he's consistently failed to clarify) handling RAS on
behalf of another compliant H.323 endpoint a possibility?
A4a (My position, with which I THINK you agree) No, on the grounds that if
gateway/IWF can find a gatekeeper and use it, so can the endpoint.
A4b (Charles) Yes.
This actually gives rise to a further question, which is (I believe) open,
probably shouldn't be:
Q5. Can an endpoint be separated from its gatekeeper by a proxy?
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