First of all, just a word to say that I am not an expert On Voice Over IP technologies...

I would like to know if there is an "on the shelf product" which allows echo cancellation over multiple lines.

to simplify my "problem", i have an operator who is speaking on a phone (phone 1), and who is hearing his voice coming from speakers which are linked to ANOTHER phone line (phone 2).

            -------------->phone 1--------------->network

Operator

            <----------Speaker<-------phone 2---------- network

I want to cancel the operator voice coming from phone 2, but only his voice.

Is there a cisco product (like Cisco® Multiflex  Trunk Dedicated Echo Cancellation (MFT ECAN)) which is able to do what i want ?

I thank you in advance for any answer

YG