[asterisk-users] Intermitent voice issues

[Alejandro Recarey]

Hi all and thanks for reading.

I am experiencing a frustrating issue with asterisk where on some
calls the volume suddenly drops to inaudible o completely fades away
for a time. If you hold on long enough (20 to 30 seconds) the sound
will come back.

My asterisk server is on a public IP, and basically acts as a VoIP
bridge receiving calls from my customers (all of whom use Grandstream
GXW400X gateways on public IP's, no NAT) and sending them to different
SIP providers. I am proxying the RTP stream through the server
(canreinvite=no).

I am sure this is an issue with my setup because this happens to
random customers calling to random destinations on any of our VoIP
providers. The symptoms are always the same: voice becomes inaudible
or fades away, most of the time the customer hangs up.

I am running CentOS 5.5 and asterisk 1.6.2.15 on 4 different servers,
all of them Dell PowerEdge.

Any ideas? I do not even know how to start debugging this issue. A SIP
trace obviously shows nothing. Any pointers would be appreciated.

Regards,

Alex