Norma Velocidad máxima Otras velocidades V.90 y X2* 56.000 bps 57.333, 54.666, 53.333, 52.000, 50.666, 49.333, 48.000, 46.666, 45.333, 44.000, 42.666, 41.333, 40.000, 38.666, 37.333, 36.000, 34.666 bps V.34+ 33.600 bps 31.200 bps V.34 28.800 bps 26.400, 24.000, 21.600, 19.200, 16.800 bps V.32bis 14.400 bps 12.000 bps V.32 9.600 bps 7.200 bps V.23 4.800 bps V.22bis 2.400 bps V.22 y Bell 212A 1.200 bps V.21 y Bell 103 300 bps