[OpenSIPS-Devel] [opensips] pua_dialoginfo: failed calls triggers sending PUBLISH errors (#142)

[Damien Sandrs]

Hi Bogdan,

The main reason why I added that setting in the first place was to workaround the SIP PUBLISH problem in OpenSIPS. We wanted to minimize the number of PUBLISH being sent.

For example, when you call a device that is BUSY, you will be notified through a PUBLISH that there was a call attempt, then that the call was finished, instantly. With the unordered PUBLISH problems, the BLF was most of the time stuck in a wrong state.

In general, even if that specific problem has been fixed, I think that it is preferable to minimize state changes on servers with many users, and many BLFs, It is probably best to be notified as soon as the call is ringing state, but not before to prevent such rapid state changes. I would keep the option, but I would apply Ovidiu's suggesting : when the publish_on_trying parameter is disabled, we should not try publishing the terminated state.

Moreover, the RFC 4235 states:

3.10. Rate of Notifications


   For reasons of congestion control, it is important that the rate of
   notifications not be excessive.  It is RECOMMENDED that the server
   not generate notifications for a single subscriber faster than once
   every 1 second.

So I think that "trying" -> "terminated" instant transitions should be prevented, and that is what the publish_on-trying option is trying to do.

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Reply to this email directly or view it on GitHub:
https://github.com/OpenSIPS/opensips/issues/142#issuecomment-30655605
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