I don' hear

I have a problem. I have installed an Asterisk with version 1.6.X and a digium TE220. When We do a call across Dahdi channel, if I talk I can hear to the other side, and vice versa. I have to be in silent to hear to the oher side.
Can any help me?

Are you using the latest Dhadi/Zaptel packages and the latest and greatest drivers?

Why do you ask this?, any bug in old versions of Dahdi/zaptel which affect of this manner?

Yes. Some older zaptel/dhadi packages/drivers had half-duplex conversation problems.

DAHDI Version: Echo Canceller: