Re: [Linphone-developers] REGISTER bug

[Klaus Darilion]

Am 25.03.2011 11:38, schrieb Guillaume BERAUDO:
> Hi Klaus,
> 
> Thanks for your email.
> 
>> From: <sip:address@hidden>;tag=3925467721
>> To: <sip:address@hidden>;tag=3925467721
>> The To header is buggy as it must not contain a tag.
> 
> Why do you thing it is buggy?
> 
> I read on http://www.ietf.org/rfc/rfc3261.txt #20.39 :
> 
> The following are examples of valid To header fields:
>    To: The Operator <sip:address@hidden>;tag=287447
>    t: sip:address@hidden

Yes, it is allowed from the grammer, but not in the context of a
registration.

The From/To tags identify dialogs. An out-of-dialog request contains
only a From-tag. An in-dialog request contains also a To-tag.

REGISTER does not create a dialog. Thus, the REGISTER is always an
out-of-dialog request. Even re-Registrations are out-of-dialog thus must
not have a to-tag (as the to-tag is generated by the UAS).

See also the RFC: http://tools.ietf.org/html/rfc3261#section-8.1.1.2

>    A request outside of a dialog MUST NOT contain a To tag; the tag in
>    the To field of a request identifies the peer of the dialog.  Since
>    no dialog is established, no tag is present.


regards
Klaus