Orit,
You still do not hear what I am saying.
So I repeat, in order to have something for November;
Can we agree to these statements for the H.323 URL in
H.323v4?
If we agree on this, can the URL format be formulated to
support these statements?
If the URL can be formulated, can it be submitted and
approved by IETF before November?
Bob
------------------------------------------------------------------
Robert
Callaghan
Siemens
Enterprise Networks
Tel:
+1.561.923.1756 Fax:
+1.561.923.1403
Email: Robert.Callaghan@ICN.Siemens.com
------------------------------------------------------------------
-----Original
Message-----
From: Orit Levin
[mailto:orit@radvision.com]
Sent: Monday, September 11, 2000
3:01 PM
To: Callaghan, Robert
Cc: ITU-SG16@mailbag.cps.intel.com
Subject: Re: Revised H.323 URL
document
Bob!
Below is
my take on the current situation.
The three of
us have the following different views on the possible use of the H.323
URL.
If I try to
map them into the H.323 "classic" picture of
EP1---GK1-------GK2---EP2 . The GKs are optional. If exist, they may contain BE
as well.
I understand
the following:
Bob:: indirect: EP1---GK1; direct: EP1 --------Zone2
Paul:: indirect: Zone1-------GK2; direct: Zone1------EP2
Orit::
Zone1-------Zone2 (with H.225.0 Q.931, LRQ or Annex G) possible between them
for a specific call.
We
"agree" that all of the scenarios should be allowed.
"It
seems like" we disagree about the priority/emergency of
each of the applications above.
Saying that,
I don't like very much to define a solution based on the
"perceived priority" of the applications.
My proposed
approach is, above all, guided by the fact, that the DESTINATION is
the one to design its URL scheme, implement and, eventually, publish its
URL(s).
The URL
-
has a key (I.e. the DNS domain) for IP resolution only
-
says what is the first H.323 protocol to contact this IP address, all the
scenarios above are addressed.
If the DNS
portion (I.e. "host") is not present, it automatically means, that
the local (pre-configured or RAS discovered) gatekeeper will resolve the
"user" name (using RAS, Annex G, another DNS lookup, other means). It
is an exception, but it is still consistent with the approach above (The local
zone is responsible for the URL scheme, it published.)
The bottom
line: I agree with the last proposal for H.323v4:
No parameters
at all. The default: H.225.0/Q.931/Setup with its default TCP port.
Paul?
Best Regards,
Orit Levin
RADVision Inc.
575 Corporate Drive Suite 420
Mahwah, NJ 07430
Tel: 1 201 529 4300 (230)
Fax: 1 201 529 3516
www.radvision.com
orit@radvision.com
-----Original Message-----
From: Callaghan, Robert <Robert.Callaghan@icn.siemens.com>
To: 'Orit Levin' <orit@radvision.com>
Cc: ITU-SG16@mailbag.cps.intel.com
<ITU-SG16@mailbag.cps.intel.com>
Date: Monday, September 11, 2000
1:53 PM
Subject: RE: Revised H.323 URL
document
Orit,
Let us try
to focus on a few points first:
(These are snippets from the thread.)
OL: Are you interested in efficiently running H.323 over the
Internet?
RC: Yes! For clarification,
this is the H.323 as defined in H.323v4 and H.225.0v4. For the November decision, there should
not be any extensions, implicit or explicit.
OL: The picture,
in my mind, is different from yours and fits the "traditional" H.323.
For every H.323 call, logically there are (at least) two GKs: source and
destination. (Physically, both of them are optional, based on the
"mode" policy inside the corresponding H.323 zones.)
RC: I agree with your model of two endpoint
each with an optional GKs based on zone policies. The source and destination policies are independent from
each other. I don't know how this
is different, as you state.
OL: By specifying in H323-URL the
"mode" of operation between the source EP and a GK, you propose to
use the URL for "publishing" the relations between the EP and
"ITS" GK PER DESTINATION! It is, indeed, very different from the
H.323 today. Moreover, you implicitly introduce a concept of a
"source" GK, being re-defined each time BY THE DESTINATION. (This
case may be considered as an additional application for the H.323 URL)
RC: I make so such assumption. In the "Direct" model, I
assume that the given address is directly callable. The routing model is not specified nor assumed. If the term "Direct" is a
problem in that the term overlaps with the routing model then the use of
"Callable" would be fine.
The use of the DNS service to convert the DNS domain to an IP address is
assumed. This is also the only use
of the DNS server. No DNS records
beyond the "A" record will be used. If the initial use of the H.323 URL could be limited to this
service.
RC:
The use of the "Indirect" or "non callable" form has
bothered me in that its use is not clearly defined. My view is that this was a means to access an H.323
repository to obtain the true address.
Apparently there are other views.
Therefore I suggest that a solution would be to drop this form for now.
OL: The natural
use of URLs is between the zones/domain. For H.323, it is an OPTION, what kind
of address resolution to propose and use. The beauty of the URL approach is
that the DESTINATION provides an option to be reached using the DNS lookup,
if it chooses so and populates properly the DNS.
RC: The may be
beautify for some; but it is definitely new. I know of nothing in H.323v4 that describes the procedures
and rules for this type of address resolution. This can be discussed as part of Annex O, after the decision
on H.323v4.
OL: We don't have to agree on the mailing list. We can spend more then
one meeting in order to reach "the consensus". In that case, I
would support the inclusion of the minimal H323-URL only (without any
parameters and without the PORT number) towards the H.323v4.
RC: I agree that it is not possible to agree to a complex solution
on the mailing list. However, I
hope that we can agree to a simple URL without any parameters or port (ouch! J) where this URL is the actual address to be used in a SETUP
message. This should not change
anything in H.323 including the use of the GK.
I hope that this helps.
Bob
------------------------------------------------------------------
Robert Callaghan
Siemens Enterprise Networks
Tel: +1.561.923.1756 Fax:
+1.561.923.1403
Email: Robert.Callaghan@ICN.Siemens.com
------------------------------------------------------------------