Subject: [SIP] Call-ID and CSeq in Registration

From: Baniel Uri-CUB001 <[email-masked]>
Date: Sun, 8 Apr 2001 07:26:11 -0500

What is the exact use a SIP server does with these two fields upon receiving a Registration request. What bad thing would have happened at the server side, if it had not received the Call-ID info? same for CSeq?
(I mean: If Call-ID serves as the key field to the client's record, we could use the <To> field?! 
As far as the CSeq goes, the spec says that the server shall not reject the reg. request even if the CSeq is out of order, so what is the use of it?)

I understand the CSeq helps the client to tell one response from the other. Same regarding Call-ID for distinguishing requests which have been sent to different servers? Is that true?

Thanks,

Uri

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From: Baniel Uri-CUB001 <[email-masked]>
Date: Sun, 8 Apr 2001 07:31:33 -0500

Oh, perhaps the job of the CSeq field at the server, is simply as in the
INVITE case, to tell retransmissions from new requests? If so, would the
server use the increasing CSeq number when doing its updates? I guess not,
since it works in an "insert" mode anyway. Is that correct?

-----Original Message-----
From: Baniel Uri-CUB001 [mailto:[email-masked]]
Sent: Sunday, April 08, 2001 7:26 AM
To: [email-masked]
Subject: [SIP] Call-ID and CSeq in Registration

What is the exact use a SIP server does with these two fields upon receiving
a Registration request. What bad thing would have happened at the server
side, if it had not received the Call-ID info? same for CSeq?
(I mean: If Call-ID serves as the key field to the client's record, we could
use the <To> field?! 
As far as the CSeq goes, the spec says that the server shall not reject the
reg. request even if the CSeq is out of order, so what is the use of it?)

I understand the CSeq helps the client to tell one response from the other.
Same regarding Call-ID for distinguishing requests which have been sent to
different servers? Is that true?

Thanks,

Uri