3Com 005699-00 -, Руководство пользователя

Страница: 50 / 101

G
LOSSARY
7-8
terminal mode
Software mode that allows direct communication
with the modem. Also known as command mode.
throughput
The amount of actual user data transmitted per
second without the overhead of
protocol
information such as start/stop bits or frame
headers and trailers. Compare with characters per
second .
V.8
The ITU-T standard specification that covers the
initial handshaking process.
V.17 fax
An ITU-T standard for making facsimile
connections at 14,400 bps, 12,000 bps, 9600 bps,
and 7200 bps.
V.21
An ITU-T standard for modems operating in
asynchronous mode at speeds up to 300 bps, full-
duplex , on public switched telephone networks.
V.22
An ITU-T standard for modem communications at
1200 bps, compatible with the Bell 212A standard
observed in the U.S. and Canada.
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