[asterisk-users] corrupt faxes

[Louis-David Mitterrand]

Hello,

Since our telco messed with our PRI in some way, we get corrupt faxes 
like these:

http://zenon.apartia.fr/stuff/corrupt_fax.pdf

We use the lastest asterisk with a TE410P and spandsp.

(for some strange reason, our neighbour company has a traditional pbx 
fed by 7 BRI's and sees the same problem)

Now the telco is trying to racket us with some "audit" to solve the 
problem. They are claiming our pbx clockrate might be responsible.

What could interefere with faxing in such a way? Could the telco have 
enabled some echo cancellation on their side?

Thanks in advance for any insight,