G.165 vs. G.168

The fax tests included in Test 10 of G.168 are meant to ensure that the echo canceler converges rapidly on initial fax handshaking sequences and that the echo canceler remains stable and does not generate unwanted echo.

Test 10A tests for convergence and stability at the calling station side on the called station identification tone and on a sequence consisting of the non-standard facilities frame, called subscriber identification frame and digital identification signal frame.

Test 10B tests for convergence and stability at the called station side on a sequence consisting of the non-standard setup frame, transmitting subscriber identification.