V.34


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V.34

(protocol)
An ITU-T standard modem serial line protocol using symbol rates of 2400, 2743, 2800, 3000, >3200 and 3429 and up to 28800 bits per second.

The official V.34 draft recommendation was titled:

Modem operating at data signalling rates of up to 28 800 bit/s for use on the general switched telephone network and on leased point-to-point 2-wire telephone-type circuits.

During the lengthy process of approval by ITU-T, many manufacturers released 28.8 kbps modems described as "V.FAST". The V.34 recommendation was ratified by ITU-T on 20 September 1994. Rockwell and US Robotics both have seats on the ITU-T, and have both released chip set/BIOS combinations that they feel will meet V.34. V.34 modems will also support V.FC if the manufacturer currently supports V.FC (e.g. Rockwell). Some (all?) V.34 modems will also support line probing.

ITU document.

V.34

An ITU standard (1994) for 28,800 bps and (1996) 31,200 and 33,600 bps analog modems using QAM modulation. Before V.34, AT&T's V.32terbo and Rockwell International's V.FC modems came on the market to provide greater speed than the V.32bis 14,400 bps standard. After V.34 was standardized at 28.8 Kbps, subsequent enhancements that raised speeds to 33.6 Kbps were folded back into V.34, and there was no change in number or designation.