asterisk users - Feb 2005 - Grandstream 486 Sending Faxes issue out TDM400P

Hi,

Hoping someone has run into the same issue.

I have an * 1.0.5 tdm400p and 2 fax machines on grandstream 486 boxes.

When a fax comes in, no problem receives it fine. When you try to send a
fax out just as the fax seems to be finishing the send you get a comms
error on the fax machine and it fails wanting to retry (tried 2
different brand fax machines same issue).

The 486's were configured to use ilbc as the codec, after looking around
I thought it might be a compression issue so I changed the 486's to alaw
with 1 TX packet per send, bandwidth not being an issue as its local
lan. Same issue.

Anyone got any ideas on what might be the issue? I used a PSTN phone on
the 486 and dialed out manually and there was no echo or noise on the
line.

James