Question : VOIP codec or routing problem??

Cisco 2600 Router
Cisco 3560 G 24 port Gig Switches
Cisco 186 ATA VOIP  (Analog to IP addapter)

Hello:

I am on a ship with 50 people on board that spend about 8 months of the year at sea to collect scientific data. If you could help me get VOIP working, you would be our hero for the week.

I have 24X7 internet access. Another two of our research ships have the same setup. I wrote an email to one and they confirmed my Audio settings to be the same as theirs. Theirs works.

On my ship, it sounds like I am getting only partial IP packets. I ruled out the PBX, by plugging in a butt set directly to the Analog phone jack on the 168 ATA.

What the signal sounds like:
--Dial tone sounds perfect:
--Configuration menu sounds perfect:
--Actual communications sounds like the Charlie Brown Cartoons. I think the principle is talking to me through VOIP. So,  I have Charlie Brown on VOIP.

I know nothing about VOIP.

Is this a routing issue, IP protocol issue, what??????

Please help me get rid of Charlie Brown.

Thanks in advance for your help!!!

Answer : VOIP codec or routing problem??

What does your configuration look like on the router and switch?