T302 Overlap Dialing

I have the following problem: Some people just can not call any of our extensions. The CDR Reports show that the last digit of the called extension was not dialed.

An example:
The dialed extension has the no. +49 30 202020-66
CDR records show that +49 30 202020-6 was dialed/received and of course, that doesn’t work…
The phone company has checked their logs, and found that the person calling did indeed dial the correct number, but that my PBX accepted the call “too early”, thus cutting off the last digit.
One might think that by dialing +49 30 202020-66x this can be outsmarted, but no… same effect.
The phone company told me to adjust the “T302 - Overlap Dial” timeout so that the last digits wouldn’t be cut off, but I just can’t find anything remotely like that in PBX.

PBX Firmware: 10.13.66-15
PBX Service Pack:

Any ideas anyone???

What type of trunk do you have ?

Not In FreePBX but in dahdi, possibly add


You will have to restart asterisk and dahdi for that to take effect