[SIPForum-discussion] Regarding 180 ringing

[Moshe Ostrovsky]

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 

 

RADVISION(r)

Delivering the Visual ExperienceTM

 

Website:                  www.radvision.com <http://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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