How can I do for eliminate Echo-Cancellation in CME in Cisco Sip Phones 7841

[LUIS TUSEN]

Hello

I have a CME and CUE already configured. How can I do, so Eliminate Echo-Cancellation in Cisco Sip Phones 7841, because when I answering an call and I speak, I hear a Echo of my owen voice, then the caller me, doesn't hear me.

Thanks.

[LUIS TUSEN]

I have a Cisco Router 2901 with Call manager Express 10.0 and Cisco Unity Express 8.6, How can I apply

the echo-cancellation commands in this platform?