[asterisk-dev] chan_datacard and RTCP

[Artem Makhutov]

Hello,

Artem Makhutov schrieb:
> Hello,
>
> Olle E. Johansson schrieb:
>>
>> 17 jan 2010 kl. 17.29 skrev Artem Makhutov:
>>
>>> Hello,
>>>
>>> I am writing chan_datacard to be able to use Huawei UMTS datacards as
>>> a GSM gateway with Asterisk.
>>>
>>> Some users have complained that their calls are disconnected after
>>> exactly 30 seconds.
>>>
>>> After some investigation it came out that they were using X-Lite as
>>> their sofphone and that X-Lite is disconnecting calls after 30
>>> seconds if it does not receive RTCP packages in that time.
>>>
>>> So the question is how can I get asterisk to send RTCP packets to
>>> X-Lite?
>>>
>>> Must I add something to chan_datacard to generate RTCP packets or
>>> should asterisk generate RTCP packets by its own?
>>> I have no clue about RTCP. Can somebody give me some hints at what I
>>> should look at?
>>
>> Asterisk generates RTCP unless there's an p2p RTP bridge, which I
>> guess won't happen if you place a call from a SIP channel to your own
>> channel. Turn on "rtcp debug" in the CLI and you'll get detailed
>> information about RTCP messaging.
>
> There is no P2P RTP bridge. The call goes directly from X-Lite to
> asterisk and from there to the GSM Network.
>
>> I have never heard anything about X-lite disconnecting because there's
>> no RTCP reports, that's very odd.
>
> In X-Lite under Options -> Advanced -> Network -> Call Inactivity you
> can select if X-Lite should disconnect the call if no RTCP data has been
> recived for a given time. By default this is enabled and set to 30 seconds.
>
>> For a bit more information about RTCP, I suggest that you read my blog
>> about an on-going project to enhance RTCP support in Asterisk:
>> http://www.voip-forum.com/asterisk/2010-01/measuring-voice-quality-asterisk/
>>
>
> Thanks, I have read this.
>
> I did some more tests with asterisk and captured the output of rtcp set
> debug on:
>
> http://pastebin.com/m36464d3d (RTCP between X-Lite and chan_datacard)
> http://pastebin.com/m3105d3f8 (RTCP between X-Lite and chan_sccp)
>
> I have captured the RTCP debug between X-Lite and chan_datacard.
>
> Then I dialed a Cisco 7970 phone connected by chan_sccp from X-Lite. The
> Cisco phone is configured not to use direct RTP. So all RTP traffic goes
> through asterisk.
>
> As faar as I understand the debug, the asterisk is sending RTCP in both
> cases. The question is why is X-Lite disconnecting after 30 seconds with
> chan_datacard and why is it not disconnecting when calling the Cisco phone?

I just set the "No RTCP Disconnect Timeout" to 15 seconds in X-Lite. And 
gues what?  X-Lite is disconnecting after 15 seconds.

Could somebody with more knowledge about RTCP check the logs and maybe 
the source of chan_datacard 
(http://www.makhutov.org/svn/chan_datacard/trunk/chan_datacard.c) and 
tell me what could be wrong here?

Or is this just a problem of X-Lite? If so, why does it work fine with 
other channels?

Many Thanks, Artem


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