Dear All, I know that echo has been discussed many times however I am still struggling to resolve it in one particular instance. The scenario is: BT PRI <---> Asterisk <---> Polycom SIP handsets. The * box box is dual xeon with 1gb ram on an Asus PCDL motherboard. I have tried various revisions of * and Zaptel without any difference. I have tried various zapata.conf settings from echotraining to playing with tx and rx gain. I will try fixing echotraining at 800 but I am not convinced that this will totally solve the issue, rather mask it a little more if indeed it does. I know that the E100P is discontinued and I wondered why ? And will the TE110P offer any echo cancelling benefits ? I am going to look into if the card is IRQ sharing although I have not seen any irq misses in zttool. Does anyone have any experience of this hardware mix and or any suggestions. Thanks, Stuart