[Asterisk-Users] Audio flutter on OH323 output?

[Michael Manousos]

Tony Mountifield wrote:
> Hi, I'm using OH323, mostly with success, to interface Asterisk to
> a provider's switch (World Telecom INX). I have noticed a particular
> effect, and I wonder whether anyone else has seen the same?
> 
> The effect is audio flutter (almost like the flutter one gets on
> MF or HF radio sometimes) which only happens intermittently.
> Audio coming into Asterisk is unaffected, as proved by using the
> Monitor app as follows:
> 
> Phone1->PSTN->Switch-(via H.323)->Asterisk(Monitor+DISA)->Switch->PSTN->Phone2.
> 
> Intermittently, each party hears the other party's audio flutter for a few
> seconds. Reviewing the recordings made by Monitor, no flutter is present,
> so the incoming audio is fine.
> 
> Note that this is a direct call. I've also noticed it on MeetMe, where
> it seems again that the flutter is on the audio leaving Asterisk.
> Different participants may hear the flutter at different times.
> 
> The system is a dual-Xeon 3GHz running Fedora Core 3 with the STABLE
> branch of Asterisk from CVS, together with oh323 0.6.5, openh323 1.13.5.3
> and pwlib 1.6.6.3.
> 
> Any suggestions would be appreciated!

Can you get an ethereal trace on a call with that problem?
Run an RTP analysis on the captured stream (Tools Menu) and save
the contents of the RTP packets in audio files. Then check if
the playback of these files is normal or not.

> 
> Cheers
> Tony

Michael.