search for: nasrt

I have a test install set up as follows Grandstream 102 ---- Asterisk ---- X100P ---- Adtran Express 3000 --- ISDN line to PSTN Most things I want to do work fine except I do have some intermittent problems with an echo. I am assuming that this is created in the link between the X100P and the Adtran terminal adaptor. I am not sure of the proper terms but on the PSTN side of the Adtran there is