nITU-T
specifies several modem standards as
nV.26
(11/88) - 2400 bits per second modem for use on 4-wire leased lines
nV.27 (11/88) - 4800 bits per second modem for use on leased lines
nV.27ter
(11/88) - 4800/2400 bits per second modem for use in the general switched
telephone
nV.29
(11/88) - 9600 bits per second modem for use on point-to-point 4-wire leased
lines
nV.90 (09/98) - 56 000 bit/s downstream and up to 33 600 bit/s
upstream modem for use in the general switched telephone