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