[asterisk-dev] [Code Review] 3546: DTMF emulation bad calculation that hurts RTP

[Matthew Jordan]

On Sun, May 18, 2014 at 1:57 AM, Petros Moisiadis <ernest0x at yahoo.gr> wrote:

>  On 05/16/2014 04:50 PM, Olle E Johansson wrote:
>
>    This is an automatically generated e-mail. To reply, visit:
> https://reviewboard.asterisk.org/r/3546/
>   Review request for Asterisk Developers.
> By Olle E Johansson.
>  *Repository: * Asterisk
> Description
>
> This code in channel.c is wrong. It first checks if we have a length. If not, we set it to a measured time, which is fine.
>
> If we have a length and it's under the minimum DTMF duration, we set it again to the measured time. In an RTP session, the duration can be under minimum, but has no relationship to the measured time between DTMF start and end. We should keep the given RTP DTMF time and use that for emulation. I have had DTMF that was extended by up to 60 ms because of this code and that really, really broke communication for these alarm panels that send many short DTMF tones.
>
> I suggest that this fix goes into 1.8 and later revisions.
>
>   Testing
>
> Hours and hours of reading DTMF logs. Countless cups of tea. A gazillion milliseconds wasted. All tested in 1.8.
>
>   Diffs
>
>    - /trunk/main/channel.c (414046)
>
> View Diff <https://reviewboard.asterisk.org/r/3546/diff/>
>
>
>
> Hello,
>
> Could this patch help with high cpu usage issue #21872?
>
>
Highly unlikely. The root cause of that performance problem has not really
been found, as it has not been reproduced on a consistent basis by any bug
marshal. This patch - at least so far - is not looking to address any
performance problems so much as DTMF emulation extending digits when it
shouldn't.

-- 
Matthew Jordan
Digium, Inc. | Engineering Manager
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
Check us out at: http://digium.com & http://asterisk.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.digium.com/pipermail/asterisk-dev/attachments/20140523/e12a50d1/attachment.html>