b410p with mISDN and IAXMODEM problem


I setup an asterisk installation with a digium b410p Bri card (mISDN driver) and hylafax with iaxmodem. I can receive faxes perfectly but I have over 80% faillures at sending. Cut pages, and many many errors.

Reading at internet I realized that there is a kind of “timing” problem. Is there something I can do with that?