Wireshark-users: Re: [Wireshark-users] Debugging intermittent audio dropout with RTP over OpenVPN
From: Andrew Martin <amartin@xxxxxxxxxxx>
Date: Thu, 10 Sep 2015 15:01:05 -0500 (CDT)
----- Original Message -----
> From: "Jeroen Eeuwes" <jeroeneeuwes@xxxxxxxxx>
> To: "Community support list for Wireshark" <wireshark-users@xxxxxxxxxxxxx>, "Andrew Martin" <amartin@xxxxxxxxxxx>
> Sent: Thursday, September 10, 2015 1:39:53 PM
> Subject: Re: [Wireshark-users] Debugging intermittent audio dropout with RTP	over OpenVPN
> 
> Hi Andrew,
> 
> >however calls involving the phones
> >connecting over the Internet intermittently
> >experience audio quality problems (e.g.
> >calls will drop audio for 15 seconds or
> >audio will be very garbled when someone
> >talks).
> 
> I have the same problem. I have a hunch the audio problems are caused by
> renegotiating the keys for the VPN by the phone. But I have not yet spent
> much time studying it.
> 

Hi Jeroen,

Are you also using Yealink phones? Do you have a copy of the OpenVPN
client config for your phones? I posted mine here, but the Yealink
support people say that the settings are correct and should work without
problems:
http://forum.yealink.com/forum/showthread.php?tid=5860

I took a closer look at it and I do see the following messages in the
OpenVPN server log whenever someone reports a "bad" call:
http://pastebin.com/62gnvjdh

A description of this can be found here:
https://openvpn.net/archive/openvpn-users/2007-07/msg00104.html

Is this what you meant by the key renegotiation disrupts the calls? If so,
it seems the solution might be to set "reneg-sec 86400" (only renegotiate
once per day) in both the client and server configs?

Thanks,

Andrew