[SIPForum-discussion] Regarding 180 ringing

[vijay kant gupta]

Thanks to all of you for giving valuable comments,

Regards
Vijay Gupta

On Wed, May 6, 2009 at 2:12 PM, Moshe Ostrovsky <mosheo at radvision.com>wrote:

>  Hi.
>
>
>
> To prevent client transaction from hanging forever in proceeding state,
> user can start an *application level timer*, which is indicated using
> Expires header in initial INVITE.
>
>
>
> RFC 3261 says:
>
> 13.2.1 Creating the Initial INVITE
>
>    The UAC MAY add an Expires header field (Section 20.19) to limit the
>
>    validity of the invitation.  If the time indicated in the Expires
>
>    header field is reached and no final answer for the INVITE has been
>
>    received, the UAC core SHOULD generate a CANCEL request for the
>
>    INVITE, as per Section 9.
>
>
>
> 13.3.1 Processing of the INVITE
>
>     If the request is an INVITE that contains an Expires header
>
>     field, the UAS core sets a timer for the number of seconds
>
>     indicated in the header field value.  When the timer fires, the
>
>     invitation is considered to be expired.  If the invitation
>
>     expires before the UAS has generated a final response, a 487
>
>     (Request Terminated) response SHOULD be generated.
>
>
>
> Hope it answers your question.
>
>
>
> Best regards,
>
>
>
> *Moshe Ostrovsky*
>
> SIP-IMS **
>
>
>
> R*A*D*V*ISION®
>
> Delivering the Visual ExperienceTM
>
>
>
> Website:                  www.radvision.com
>
>
>
> *From:* discussion-bounces at sipforum.org [mailto:
> discussion-bounces at sipforum.org] *On Behalf Of *Garron, James
> *Sent:* Tuesday, May 05, 2009 10:49 PM
> *To:* vijay kant gupta; discussion at sipforum.org
> *Subject:* Re: [SIPForum-discussion] Regarding 180 ringing
>
>
>
> Interesting question.
>
>
>
> I believe that once you receive the provisional response putting the call
> into the proceeding state you would reset Timer B (T1*64), and that the call
> would stay in the proceeding state until receiving a final response of until
> Timer B is expires.  Of course if there were a retransmission of the
> provisional response that would reset Timer B again.
>
>
>
> Jim
>
>
>
>
>  ------------------------------
>
> *From:* discussion-bounces at sipforum.org [mailto:
> discussion-bounces at sipforum.org] *On Behalf Of *vijay kant gupta
> *Sent:* Tuesday, May 05, 2009 1:48 AM
> *To:* discussion at sipforum.org
> *Subject:* [SIPForum-discussion] Regarding 180 ringing
>
>
>
> Hi ,
>
> My question is
>
> Q if uac receive 180 ringing and he didn't get any final response "under
> proceeding state so at that time which timer get expire and what is the
> duration for that timer?
>
>
> Fig:--
>
>                                |INVITE from TU
>
>              Timer A fires     |INVITE sent
>
>              Reset A,          V                      Timer B fires
>
>              INVITE sent +-----------+                or Transport Err.
>
>
>
>
>
>                +---------|           |---------------+inform TU
>
>                |         |  Calling  |               |
>
>                +-------->|           |-------------->|
>
>                          +-----------+ 2xx           |
>
>
>
>
>
>                             |  |       2xx to TU     |
>
>                             |  |1xx                  |
>
>     300-699 +---------------+  |1xx to TU            |
>
>    ACK sent |                  |                     |
>
>
>
>
>
> resp. to TU |  1xx             V                     |
>
>             |  1xx to TU  -----------+               |
>
>             |  +---------|           |               |
>
>             |  |         |Proceeding |-------------->|
>
>
>
>
>
>             |  +-------->|           | 2xx           |
>
>             |            +-----------+ 2xx to TU     |
>
>             |       300-699    |                     |
>
>             |       ACK sent,  |                     |
>
>
>
>
>
>             |       resp. to TU|                     |
>
>             |                  |                     |      NOTE:
>
>             |  300-699         V                     |
>
>             |  ACK sent  +-----------+Transport Err. |  transitions
>
>
>
>
>
>             |  +---------|           |Inform TU      |  labeled with
>
>             |  |         | Completed |-------------->|  the event
>
>             |  +-------->|           |               |  over the action
>
>
>
>
>
>             |            +-----------+               |  to take
>
>             |              ^   |                     |
>
>             |              |   | Timer D fires       |
>
>             +--------------+   | -                   |
>
>
>
>
>
>                                |                     |
>
>                                V                     |
>
>                          +-----------+               |
>
>                          |           |               |
>
>
>
>
>
>                          | Terminated|<--------------+
>
>                          |           |
>
>                          +-----------+
>
>
>
>                  Figure 5: INVITE client transaction
>
>
>
> Need to modify RFC 3261 for handling that response or not , please specify your valuable comment .
>
>
>
>
>
>
>
> ThanKs in advance
>
>
>
> Regards
>
>
>
> Vijay Gupta
>
>
>
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