Thanks for your prompt reply.
But in your answer 2 & 3 you still also not told what should be correct
behavior whether client should not send PRACK or should?
Please reply the MUST or SHOULD behavior of the client.
I have one suggestion as RFC is silent in this issue whether server B will
take action that if 100rel is not present in Supported header but present in
Require header in INVITE request then discard the call. Because if server B
sends RPR client A will not understand as Client A not supports.
Again if server B not sends RPR then also Client A will not accept the
provisional response as he mandates only Reliable Provisional Response.. Both
the way Client B cannot send any proper response.
This situation will become more complex if original INVITE request contain no
offer. Because first RPR must contain a offer(as perRFC 3262).But Client A will
not understand that RPR. Server B will be also not able to send Final response
for INVITE as his RPR containing a offer not got any answer. Call cannot be
established.
So server B will discard the INVITE with Require:100rel but no
Supported:100rel as a Bad request
Thanks
SOURAV DHAR CHAUDHURI
----- Original Message ----
From: prasanna c <[EMAIL PROTECTED]>
To: Sourav Dhar Chaudhuri <[EMAIL PROTECTED]>
Sent: Friday, 28 March, 2008 12:24:42 PM
Subject: RE: [SIPForum-discussion] For sending PRACK for a RPR is it mandatory
to have Supported:100rel in IN
.hmmessage P
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margin:0px;padding:0px;}
body.hmmessage
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FONT-SIZE:10pt;FONT-FAMILY:Tahoma;}
1. If caller A INVITE has Require:100rel and if callee B doesn't support
100rel, then he would reject the invite with 'Bad extension' response. callee
B cannot accept the call if he doesn't support 100rel and if the INVITE
contains 'Require:100rel'.
2. There is no explicit statements in RFC indicating Require means supported.
It is like somebody asking me to talk in 'French', but that person will not
respond/understand if I talk in 'French'.
3. Let's expand scenario #1. Assume caller A sends INVITE with 'Require:100rel'
but with no 'supported:100rel'. callee B has 'supported:100rel'. Now on
receiving INVITE, callee B sends provisional response (say 180 ringing) with
'Require:100rel'. Now if caller A doesn't support then he will not send PRACK.
Then callee B would keep retransmitting the provisional response '180 ringing'.
This is contradicting the 'require' in the original INVITE.
Date: Fri, 28 Mar 2008 10:08:42 +0530
From: [EMAIL PROTECTED]
Subject: RE:[SIPForum-discussion] For sending PRACK for a RPR is it mandatory
to have Supported:100rel in INVITE while it already contains Require:100rel in
INVITE
To: [EMAIL PROTECTED]
.ExternalClass DIV
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Thanks for your reply but I have this doubt.
1. Caller A sends a INVITE request with both Supported:100rel & Require:100rel
to callee B.
(In Callee B contains Require:100rel but no Supported:100rel. means if any time
callee B makes another INVITE to a new Callee C that INVITE request will
contain Require:100rel but no Supported:100rel.)
So now callee B will send RPR or not as it has the feature Require:100rel but
no Supported:100rel?
Finally you have said in first line in your email that "Require:100rel in
INVITE also implies that the caller supports 100rel" From which portion of
which RFC you are making this point. Because if your statement is taken then I
will also get the answer of question which I asked in this letter.
Thanks
SOURAV DHAR CHAUDHURI
----- Original Message ----
From: prasanna c <[EMAIL PROTECTED]>
To: Sourav Dhar Chaudhuri <[EMAIL PROTECTED]>
Sent: Friday, 28 March, 2008 9:03:06 AM
Subject: RE: [SIPForum-discussion] For sending PRACK for a RPR is it mandatory
to have Supported:100rel in IN
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{font-size:10pt;font-family:Tahoma;}
Hi,
Require:100rel in INVITE also implies that the caller supports 100rel. But
'supported:100rel' is more relavant in INVITE than 'Require:100rel'. It is
usually the callee who decides whether he needs his response to be ACKED by the
caller.
2. Require:100rel in INVITE is demanding the callee to support 100rel. So if
the callee puts 'Require:100rel' in his provisional response, the caller MUST
send PRACK. If the callee doesn't put 'require:100rel' in his provisional
response, then obviously the caller will not send PRACK.
Regards,
Prasanna
Date: Thu, 27 Mar 2008 18:06:11 +0530
From: [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Subject: [SIPForum-discussion] For sending PRACK for a RPR is it mandatory to
have Supported:100rel in INVITE while it already contains Require:100rel in
INVITE
.ExternalClass DIV
{}
Hi,
I have a doubt is it mandatory to have Supported:100rel in INVITE
request while it already contains Require:100rel in INVITE.
2. One more question is it possible that a Caller cannot send PRACK for a
Reliable Provisional Response(RPR) as it contains Require:100rel but no
Supported:100rel in its INVITE request..
I am asking the second question because if that the same capability is
present in Callee so whether after receiving any INVITE with Require:100rel ,
whether callee will be not be able to send RPR.
Thanks
SOURAV DHAR CHAUDHURI
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