Chris,
Gettin' closer.
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 compliant endpoint.
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.
Paul Long ipDialog, Inc.
-----Original Message----- From: Chris Wayman Purvis [mailto:cwp@ISDN-COMMS.CO.UK] Sent: Friday, December 01, 2000 3:46 AM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: Third party registration/group registration
Paul,
I think we're starting to converge. Let's separate this out now, into separate questions:
Q1. Are endpoint devices (in which term I include gateways etc throughout this 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 in the system, and hence whether or not to use RAS? A2a (Your position as I understand it.) Configuration, discovery on startup, 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 discovered gatekeepers, where there is at least one gatekeeper in the system, and fails (RRJ)? A3a (My position) Shut itself down. A3b (Anybody elses) ???
Q4. Is Charles's actual application, where one entity is registering and hence 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 the 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, and probably shouldn't be: Q5. Can an endpoint be separated from its gatekeeper by a proxy?
Regards, Chris
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv@mailbag.intel.com