Subject: Re: [Sip] is supported and require is Mandatory in INVITE request

From: "ZHANG Rocky F" <[email-masked]>
Date: Wed, 20 Feb 2008 09:18:18 +0800

Yes.
 
According to RFC 3261, Supported and Require are optional. But if they
are needed, they must be present.
These two header fields are all for standard SIP extensions.

Best Regards,
 
===========================================
Fanwen zhang
FS5000 CPE IOT, Alcatel-Lucent Qingdao, R&D
Tel: +86-532-88615493
Email:[email-masked]
===========================================

________________________________

From: [email-masked] [mailto:[email-masked]] On Behalf Of
[email-masked]
Sent: Tuesday, February 19, 2008 7:21 PM
To: [email-masked]; [email-masked]
Subject: Re: [Sip] is supported and require is Mandatory in INVITE
request

Hi Sudhir,
  "Supported" and "Require" are known as headers rather than methods.
  These two headers have the following significance as per RFC 3261 :
   
20.32 Require
The Require header field is used by UACs to tell UASs about options
   that the UAC expects the UAS to support in order to process the
   request.
 
20.37 Supported
   The Supported header field enumerates all the extensions supported by
   the UAC or UAS.

  If INVITE contains just "Supported" header, the UAS "MAY" send the
non-100 responses reliably as stated in RFC 3262
 
  If INVITE contains "Require" header, the UAS "MUST" send the non-100
responses reliably. If it does not support this extension, it should
respond to the INVITE with "420 Bad Extension" response.
 
  Its valid for a UAC to send INVITE with just "Require: 100 rel" header
as well.
Best Regards,
Rekha
(ESN : 6-877-5834)
(PSTN : 81168)

________________________________

From: [email-masked] [mailto:[email-masked]] On Behalf Of
Sudhir Kumar Reddy
Sent: Tuesday, February 19, 2008 4:00 PM
To: [email-masked]
Subject: [Sip] is supported and require is Mandatory in INVITE request

Hi All,

Is supported and require methods are required for INVITE request (RFC
3262) or any of method(either Supported or require) will suffice for
INVITE for Provisional ACK. Because I see in one of INVITE(from server)
sending only require: 100Rel, but there is no Supported Header.

Should we treat as complete or incomplete request?

Any response is highly appreciated. 

Thanks in Advance
Sudhir 
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