I have searched the threads on the ata2 and have installed it correctly. I have this behind a compact ICS using the third line for system,fax and dsl. All works well, but my question is ringing on system phones when a fax comes in. I was under the impression that the ata2 would sense the fax call and take it before it rang on the system. I have checked programing and cannot find anything on this. Any help would be appreciated.