Asterisk TDM2400P V90

My configuration T2 -> asterisk -> FXS > Multitech modem (V90).
I turn off echocanceller for my FXS channel, change txgain/rxgain without success.
Multitech get a call but hangup after 10-15 seconds.
I got normal hangup cause (16).
When I replace Multitech modem with a fax machine it works well.

Any idea ?

I tried latency = 6 with wctdm200p driver.
Looks better cause I get more logs into Windows journal but … it does not work.
Any idea ?