Multi-Tech Systems MVP120 - Manual (Page 101)

101
Glossary
Multi-Tech Systems, Inc. MultiVOIP User Guide
Trunk: A communication line between two switching systems or offices. Central office trunks connect a PBX to the switching
system at the central office. A tie trunk connects two PBXs.
TSR (terminate and stay resident): A software program that remains active and in memory after its user interface is closed.
Similar to a daemon in UNIX environments.
Tunneling: Encapsulation data in an IP packet for transport across the Internet.
Twisted pair wiring: A type of cabling with one or more pairs of insulated wires wrapped around each other. An inexpensive wiring
method used for LAN and telephone applications, also called UTP wiring.
U
UART (Universal Asynchronous Receiver/Transmitter) (pronounced "you art"): A chip that transmits and receives data on the
serial port. It converts bytes into serial bits for transmission, and vice versa, and generates and strips the start and stop bits
appended to each character.
UNIX: An operating system developed by Bell Laboratories that features multiprogramming in a multi-user environment.
Unshielded Twisted Pair (UTP): Telephone-type wiring. Transmission media for 10Base-T.
V
V.25bis: An ITU-T standard for synchronous communications between a mainframe or host and a modem using HDLC or other
character-oriented protocol.
V.54: The ITU-T standard for local and remote loopback tests in modems, DCEs and DTEs. The four basic tests are:
• local digital loopback (tests DTE send and receive circuits),
• local analog loopback (tests local modem operation),
• remote analog loopback (tests comm link to the remote modem), and
• remote digital loopback (tests remote modem operation).
Virtual Circuit: A logical connection. Used in packet switching wherein a logical connection is established between two devices at
the start of transmission. All information packets follow the same route and arrive in sequence (but do not necessarily carry a
complete address).
Z
Zone: A collection of all H.323 endpoints and MCUs managed by a single Gatekeeper. A zone must include may include LAN
segments connected by using routers.