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Summary:ASTERISK-17489: Choppy audio into ConfBridge from IAX call when jitterbuffer=yes
Reporter:Giles MOss (gilester)Labels:
Date Opened:2011-02-28 12:56:13.000-0600Date Closed:2011-06-04 10:21:55
Priority:MinorRegression?No
Status:Closed/CompleteComponents:Applications/app_confbridge
Versions:1.8.3 Frequency of
Occurrence
Related
Issues:
Environment:Attachments:
Description:I'm using 2 Asterisk servers (one production machine at 1.6.2, one development machine at 1.8.3) connected with an IAX trunk across a LAN. One SIP phone on each server. Each phone calls into a ConfBridge conference on the 1.8.3 Asterisk.

When the IAX jitterbuffer is enabled (using the default settings in the iax.conf file), audio into the ConfBridge conference FROM the IAX call is very choppy and entirely unusable.

Audio in the other direction is fine. Audio between ConfBridge members on the same Asterisk is fine. Audio from an IAX call directly to the SIP handset is fine - so it seems to be an interaction between the IAX jitterbuffer and ConfBridge.

I have no DAHDI modules in this server and "timing test" reveals:

>Attempting to test a timer with 50 ticks per second.
>Using the 'timerfd' timing module for this test.
>It has been 1003 milliseconds, and we got 50 timer ticks

Also, the LAN shouldn't have any jitter on it. During the ConfBridge call, iax2 show channels alternates between showing:

>Channel               Peer             Username    ID (Lo/Rem)  Seq (Tx/Rx)  Lag      Jitter  JitBuf  Format  FirstMsg    LastMsg
>(None)                192.168.10.2     (None)      00121/00000  00001/00000  00000ms  0000ms  0040ms  unknow  Tx:POKE     Tx:POKE
>IAX2/tred51.net-9616  192.168.10.2     tred51.net  09616/18419  00025/00026  00040ms  0151ms  0200ms  ulaw    Rx:NEW      Tx:ACK
2 active IAX channels

and showing:

>Channel               Peer             Username    ID (Lo/Rem)  Seq (Tx/Rx)  Lag      Jitter  JitBuf  Format  FirstMsg    LastMsg
>IAX2/tred51.net-9616  192.168.10.2     tred51.net  09616/18419  00025/00026  00040ms  0151ms  0200ms  ulaw    Rx:NEW      Tx:ACK
1 active IAX channel

The channel (None) in the first example comes and goes. I have no idea what it is doing, perhaps it's a red herring?
Comments:By: Alec Davis (alecdavis) 2011-02-28 14:39:41.000-0600

in asterisk.conf try:

[options]
internal_timing = yes
By: Giles MOss (gilester) 2011-02-28 15:48:59.000-0600

Thanks,

Tried that, makes no difference to the choppy audio.
By: David Vossel (dvossel) 2011-05-06 17:13:32

If you are willing to use Trunk, ConfBridge has just been completely revamped and includes a jitterbuffer in it that appears to work pretty well.
By: David Vossel (dvossel) 2011-05-06 17:13:46

If you are willing to use Trunk, ConfBridge has just been completely revamped and includes a jitterbuffer in it that appears to work pretty well.
By: Leif Madsen (lmadsen) 2011-06-04 10:21:54

A lot of issues have been resolved with the jitterbuffer and ConfBridge lately, and this may even be an issue with res_timing_timerfd, which is also getting a fix as soon as ASTERISK-16711 is closed. Please test with the latest 1.8 branch after the issue is closed, and open a new issue if you continue to have problems.