[asterisk-users] Best timing source?

Joshua Colp jcolp at digium.com
Tue Apr 5 16:35:43 CDT 2016

Carlos Chavez wrote:
> On 4/5/16 3:17 PM, Joshua Colp wrote:
>> Carlos Chavez wrote:
>>> I am currently having a voice quality problem with one of our Asterisk
>>> servers. We have checked the network and we have found no problems that
>>> could cause the voice to sound cracked and with small interruptions. I
>>> am looking at the timing source for Asterisk and it is currently using
>>> timerfd even though we have an E1 card installed. Is timerfd better than
>>> dahdi? Any recommendations to test if timing may be a problem for voice
>>> quality and DTMF?
>> What is the scenario and the channels involved? Timing is only used
>> for things such as playback, music on hold, and ConfBridge. If it's
>> strictly a two party call then Asterisk forwards media as received.
> The problem appears on all calls, no matter the source or destination.
> There are desk phones, softphones and a couple SIP trunks to another
> office. They all experience the problem. Calls between extensions, from
> or to the E1, from or to trunks. The only scenario left to try is
> connecting calls only via the E1 so we completely eliminate the network
> side of things and se if we get the same behaviour. During calls you can
> hear some background noice and interruptions in the voice. DTMF fails
> when we try to dial to external IVR.
> I do not really believe that the fault is in the Asterisk server but I
> have to eliminate all posibilities on my side before I can lay blame on
> the network infrastructure. I was also just wondering if DAHDI would not
> be a better timing source for Asterisk since it is hardware based?

Either timerfd or dahdi should perform the same. I wouldn't expect dahdi 
to improve things unless something was really wrong on the system itself.

Joshua Colp
Digium, Inc. | Senior Software Developer
445 Jan Davis Drive NW - Huntsville, AL 35806 - US
Check us out at: www.digium.com & www.asterisk.org

More information about the asterisk-users mailing list