[SIPForum-discussion] Header Replaces and Parameter Replaces

[Doug Sauder]

The Replaces "parameter" here is a header field in the URI.  See section 
19.1.1 in RFC 3261.

--
Doug

Thomas_Young at 3com.com wrote:
>
> Hi All,
>
>     RFC 3515 defines a Refer method and Refer-to header, and gives us 
> an example of Refer-to header with Replaces parameter below:
>       Refer-To: <sip:_dave at denver.example.org_ 
> <mailto:dave at denver.example.org>?Replaces=12345%40192.168.118.3%3Bto-tag%3D12345%3Bfrom-tag%3D5FFE-3994>
>
> Unfortunately, I can't see any formal description about this Replaces 
> parameter this spec.
>    
>
>  
>     RFC3891 defines the Replaces header with following syntax/format:
>        Replaces = "Replaces" HCOLON callid *(SEMI replaces-param)
>       replaces-param = to-tag / from-tag / early-flag / generic-param
>       to-tag = "to-tag" EQUAL token
>       from-tag = "from-tag" EQUAL token
>       early-flag = "early-only"
>
>     Examples:
>       Replaces: _98732 at sip.example.com_ <mailto:98732 at sip.example.com> 
> ;from-tag=r33th4x0r ;to-tag=ff87ff
>       Replaces: 12adf2f34456gs5;to-tag=12345;from-tag=54321;early-only
>       Replaces: _87134 at 171.161.34.23;to-tag=24796;from-tag=0_ 
> <mailto:87134 at 171.161.34.23;to-tag=24796;from-tag=0>
>
> Please notice: this Replaces header has little bit different format 
> from tha above Replace parameter which has some unfixed separators 
> like ?,  %3B,%D.
>  
>
>    Also RFC3891specifies that Replaces header can be only used in 
> Invite method as below:
> The Replaces header field indicates that a single dialog identified by 
> the header field is to be shut down and logically replaced by the 
> incoming INVITE in which it is contained. It is a request header  
> only, and defined only for INVITE requests......
>
>       Header field    where   proxy   ACK  BYE  CAN  INV  OPT  REG  MSG
>      ------------    -----   -----   ---  ---  ---  ---  ---  ---  ---
>      Replaces          R              -    -    -    o    -    -    -
>
>
>                                      SUB  NOT  REF  INF  UPD  PRA  PUB
>                                      ---  ---  ---  ---  ---  ---  ---
>      Replaces          R              -    -    -    -    -    -    -
>
>
>
>
>  Here I'm just wondering why RFC3515 just gives an example of Replaces 
> parameter in the Refer-to header without any formal description about 
> its syntax or format(how to parse the unfixed separators), even I know 
> RFC5359(SIP Service Examples) and RFC5589(SIP Call 
> Control-Transfer)tell us how to use it.
>
>
> Thanks and best regards
>
>  *Thomas Young*
> Please consider the environment before printing this e-mail.
> ________________
> CONFIDENTIALITY NOTICE: This e-mail message, including any attachments,
> is being sent by 3Com for the sole use of the intended recipient(s) and
> may contain confidential, proprietary and/or privileged information.
> Any unauthorized review, use, disclosure and/or distribution by any 
> recipient is prohibited.  If you are not the intended recipient, please
> delete and/or destroy all copies of this message regardless of form and
> any included attachments and notify 3Com immediately by contacting the
> sender via reply e-mail or forwarding to 3Com at postmaster at 3com.com. 
>         
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> This is the SIP Forum discussion mailing list
> TO UNSUBSCRIBE, or edit your delivery options, please visit http://sipforum.org/mailman/listinfo/discussion
> Post to the list at discussion at sipforum.org
>   
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sipforum.org/pipermail/discussion/attachments/20100127/1f51f446/attachment-0002.html>