V.24

standard The ITU-T standard defining interchange

circuits between DTE and DCE. V.24 is the ITU-T

equivalent of EIA standard EIA-232C.

V.24 recommends 12 modem carrier frequencies that will not

interfere with Dual Tone Multi-Frequency or other telephone

control tones. These are:

GROUP A = 920 Hz, 1000 Hz, 1080 Hz, 1160 Hz

GROUP B = 1320 Hz, 1400 Hz, 1480 Hz, 1560 Hz

Group C = 1720 Hz, 1800 Hz, 1880 Hz, 1960 Hz

(1995-03-02)