I have a 6 - 7912's. I have a TDM2402E echo cancel card. Asterisk 1.2.12.1 Some times extension to extension the audio is only heard one way. Some times extension to TDM2402 calls audio is only heard one way. I have turned off the echo suppression on the 7912's config. Any idea why it would be doing this? Something to try? THanks, Jerry