Lucent Technologies PortMaster - Manual (Page 345)

Glossary
Glossary-35
User Datagram Protocol
See UDP.
UUCP
UNIX-to-UNIX Copy Program. Interactive communication system for connecting two
UNIX computers to send and receive data.
V
V.120
An ITU-T standard for performing asynchronous rate adaptation into ISDN.
V.25bis
An ITU-T standard defining how to dial on synchronous devices such as ISDN or switched
56Kbps.
V.32bis
An ITU-T standard that extends the V.32 connection range from 4800bps to 14.4Kbps.
V.32bis modems fall back to the next lower speed when line quality is impaired, and fall
back further as necessary. They fall forward to the next higher speed when line quality
improves.
V.34
An ITU-T standard that allows data rates as high as 28.8Kbps.
V.35
The ITU-T standard for data transmission at 48Kbps over 60kHz-to-108kHz group band
circuits. It includes the 35-pin V.35 connector specifications normally implemented on a
modular RJ-45 connector.
variable-length subnet mask
See VLSM.
virtual circuit
A logical connection between two endpoints on a switched digital network. Virtual
circuits can be switched or permanent. A switched virtual circuit (SVC) is used when you
make an ordinary telephone call, an ISDN connection, or a V.25 switched 56Kbps
connection. A permanent virtual circuit (PVC) is used in Frame Relay. See also PVC;
SVC.