asterisk users - Aug 2019 - ConfBridge audio issues

We have a system where two calls are in a ConfBridge with recording.  This is
Asterisk 16.3.0

Channel A seems to work perfectly.  Wireshark is showing the RTP to/from working
fine and having no jitter/lag issues.  This call hears everything from channel
B.

Channel B we have more issues capturing a wireshark trace because their channel
can be in the system for hours.
When the two calls are in the ConfBridge, Channel B is the first to speak. 
Everything seems perfectly fine.  Channel A hears it well and ConfBridge
recording sounds good.
Then, channel B replies.  Audio from channel B seems fine in wireshark (no
jitter/lag).  However, the ConfBrdge recording and channel B indicate garbled
audio.

This only happens for the first couple seconds channel B talks.
After that, everything seems to be perfectly fine.


For each channel added to the ConfBridge, the user profile has...
jitterbuffer = yes
denoise = no
dsp_drop_silence = yes
dsp_silence_threshold = 2500
dsp_talking_threshold = 160

On the bridge profile.
internal_sample_rate = 0
mixing_interval = 20
jitterbuffer is not being set.  According to the wiki, this defaults to no
binaural_active is not being set.  According to the wiki, this defaults to no


One other possible coincidence in the samples I have received, channel B seems
to always start talking roughly 2500 ms into the ConfBrdge.  Could this static
audio be occurring due to the dsp_drop_silence and the dsp_silence_threshold
hitting at 2500 ms?

Does anyone have any suggestions?

Dan
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.digium.com/pipermail/asterisk-users/attachments/20190805/ef69eac0/attachment.html>

On Monday 05 August 2019 at 19:54:50, Dan Cropp wrote:
> Channel B is the first to speak.  Everything seems perfectly fine.  Channel
A
> hears it well and ConfBridge recording sounds good. Then, channel B
replies.
Um, did Channel A say something in the meantime?

Or did you mean "Channel A replies"?

In which case...
> Audio from channel B seems fine in wireshark (no jitter/lag).  However, the
> ConfBrdge recording and channel B indicate garbled audio.
So, which channel speaks first, which replies, and which has garbled audio in 
the recording?


Antony.

-- 
"I estimate there's a world market for about five computers."

 - Thomas J Watson, Chairman of IBM

                                                   Please reply to the list;
                                                         please *don't* CC
me.

Sorry, for not being clearer.

Channel A and B added to the ConfBridge.  Same settings for both user profiles.
Channel B starts speaking.  Their audio makes it through ConfBridge to Channel A
perfectly fine.

Now, Channel A speaks to reply to question asked.  Channel B's audio is fine
in Wireshark trace to Asterisk box.

The ConfBridge recording has the garbled audio.
Channel A hears the garbled audio as well.

If it was network/jitter related, I would expect wireshark to indicate some
jitter/lag issues in the audio from Channel B to Asterisk.  That doesn't
seem to be the case.

Since the ConfBridge recording contains the garbled audio, my thought is I'm
doing something wrong with the settings.
Not sure what setting would cause this.

Could it be the jitterbuffer enabled on each ConfBridge user's profile?
Could it be the dsp_drop_silence?

Oddly enough, this happened on Friday to several calls.  Over the weekend, they
had no issues.  Also, today they have experienced no issues.

Additional information.
Channel A and B are using ulaw codec.
The recording in the ConfBridge is being transcoded to gsm for the recording.

Dan

-----Original Message-----
From: asterisk-users <asterisk-users-bounces at lists.digium.com> On
Behalf Of Antony Stone
Sent: Monday, August 5, 2019 2:18 PM
To: Asterisk Users Mailing List - Non-Commercial Discussion <asterisk-users
at lists.digium.com>
Subject: Re: [asterisk-users] ConfBridge audio issues

On Monday 05 August 2019 at 19:54:50, Dan Cropp wrote:
> Channel B is the first to speak.  Everything seems perfectly fine.  
> Channel A hears it well and ConfBridge recording sounds good. Then, channel
B replies.
Um, did Channel A say something in the meantime?

Or did you mean "Channel A replies"?

In which case...
> Audio from channel B seems fine in wireshark (no jitter/lag).  
> However, the ConfBrdge recording and channel B indicate garbled audio.
So, which channel speaks first, which replies, and which has garbled audio in
the recording?


Antony.

-- 
"I estimate there's a world market for about five computers."

 - Thomas J Watson, Chairman of IBM

                                                   Please reply to the list;
                                                         please *don't* CC
me.

-- 
_____________________________________________________________________
-- Bandwidth and Colocation Provided by http://www.api-digital.com --

Check out the new Asterisk community forum at: https://community.asterisk.org/

New to Asterisk? Start here:
      https://wiki.asterisk.org/wiki/display/AST/Getting+Started

asterisk-users mailing list
To UNSUBSCRIBE or update options visit:
   http://lists.digium.com/mailman/listinfo/asterisk-users