3Com 3C900B Installation And Operating Instructions Manual page 115

V.22 bis
An ITU-T standard for modem communications at 2400
bps. The standard includes an automatic link negotiation
fallback to 1200 bps and compatibility with Bell
212A/V.22 modems.
V.27 ter
An ITU-T standard for facsimile operations that specifies
modulation at 4800 bps, with fallback to 2400 bps.
V.29
An ITU-T standard for facsimile operations that specifies
modulation at 9600 bps, with fallback to 7200 bps.
V.32
An ITU-T standard for modem communications at 9600
bps and 4800 bps. V.32 modems fall back to 4800 bps
when line quality is impaired.
V.32 bis
An ITU-T standard that extends the V.32 connection
range: 4800, 7200, 9600, 12,000, and 14,400 bps. V.32 bis
modems fall back to the next lower speed when line
quality is impaired, fall back further as necessary, and also
G
LOSSARY
fall forward (switch back up) when line conditions
improve (see online fall back/fall forward ).
V.34
An ITU-T standard that currently allows data rates as high
as 28,800 bps.
V.34+
An enhancement to V.34 that enables data transfer rates as
high as 33,600 bps.
V.42
An ITU-T standard for modem communications that
defines a two-stage process of detection and negotiation
for LAPM error control .
V.42 bis
An extension of ITU-T V.42 that defines a specific data
compression scheme for use during V.42 connections.
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