I have a Valcom door answer system (speaker with a button to request entry) and it connects to a LS trunk port on the 3300. The problem I am having is that for the first several seconds of a call the called party (anyone inside the customer site) can hear themselves echo back in the handset. You can't hear it over the speaker outside. All of the phones are IP sets.
Any ideas? I assume this would be an option in the circuit descriptor for the trunks, I just don't know where to start.