V.26ter

V.26ter is from 1984 and supports asynchronous and synchronous transmission with differential phase shift ke ying( DPSK) from modems over dial-up lines. V.26ter is for duplex operation at .200/2,400 bit/s and echo cancellation.

ITU designations with the suffix "ter" are the third generation of a protocol or interface. This designation is an older Latin term for "three times".