<protocol> An ITU-T standard modem serial line
protocol allowing download speeds of up to 56 kbps with
upload speeds of 33.6 kbps. V.90 modems are designed for
connections that are digital at one end and have only one
digital-to-analogue conversion.
As of 1998-02-06 the V.90 standard, formerly called V.pcm, has
been given final approval by ITU-T. On 1998-10-27 the ITU-T
announced that approval of the V.90 standard was completed.
Interoperability testing is complete or in progress for
several modem manufacturers. The V.90 standard reconciles two
competing standards, X2 and K56flex.
The ITU-T has initiated the approval process for a new
all-digital version of the protocol, to be known as V.91.
