[Asterisk-Users] Pops in Call Recordings Tied to Dropped Audio in Calls

[Matt Roth]

Kevin P. Fleming wrote:

> Matt Roth wrote:
>
>> We have no hardware timing device on the box (no Zap hardware) and 
>> are using the 2.6 kernel as the timing source.  Digium tech support 
>> told us this is better than ztdummy, which we were using before.  We 
>> experienced the same problems then, as well.  Could a lack of a 
>> hardware timing source be our problem?
>
>
> If you don't have ztdummy loaded, you don't have a timing source. 
> Asterisk does not take timing from the 'kernel', although ztdummy has 
> a mode where it can do so.

That advice about not loading ztdummy came from our paid support, 
including the bit about Asterisk falling back to the kernel for timing 
if no other source is available.  It's concerning to me, to say the 
least, that we are paying for misinformation.  We are now running 
Asterisk in a production environment with no timing source.  We can't 
change this until the end of the business day.  Luckily, only our MOH 
*should* be affected, but we are trying to troubleshoot problems and 
introducing any source of strange behavior makes that more difficult.

We also wasted time last night testing whether or not removing ztdummy 
solved our problem.  Paid support time (since we were on call with 
Digium while doing the testing) as well as time that could've been used 
to look into real solutions.  I'm not asking anyone to fix the problem 
for us, but I would like some legitimate feedback on its possible 
sources.  From the list, I consider it a gift.  From paid tech support, 
I consider it a responsibility.

Does ztdummy fall to the kernel mode by default, or does it have to be 
configured to do so?

> Regardless, if the call is SIP to SIP, a timing source is not relevant 
> for this problem. 

Noted.

Matthew Roth
InterMedia Marketing Solutions
Software Engineer and Systems Developer