3Com Courier, Reference, Page: 202 / 204

12 G
LOSSARY
products control Terminal mode as well as enable more complex
operations, including file transmission and saving received files.
throughput The amount of actual user data transmitted per second without the
overhead of protocol information such as Start and Stop bits or frame
headers and trailers. Compare characters per second.
transmission rat See bit rate.
UART See Universal Asynchronous Receiver/Transmitter.
Universal
Asynchronous
Receiver/Transmitter
(UART)
A computer chip that controls the signaling that goes on through a
computer's serial port.
UTP (Unshielded
Twisted Pair)
Twisted insulated copper wires bundled into an unshielded cable,
commonly used in telephone wiring systems. Grades of UTP include
DTP (Datagrade Twisted Pair) and DIW (Distributed Inside Wire).
V.8 ITU-T recommendation that defines procedures for starting and endin
sessions of data transmission.
V.17 An ITU-T standard for facsimile operations that specifies modulation at
14.4 Kbps, with fallback to 12 Kbps.
V.21-Fax An ITU-T standard for facsimile operations at 300 bps.
V.21-Modem An ITU-T standard for modem communications at 300 bps. Modems
made in the U.S. or Canada follow the Bell 103 standard. However, the
modem can be set to answer V.21 calls from overseas
V.22 A 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.23 An ITU-T standard for modem communications at 1200 bps with a 75
bps back channel. Used in the U.K
V.25 An ITU-T standard for modem communications. Among other things,
V.25 specifies an answer tone different from the Bell answer tone. All