ADTRAN 1200212L1, Руководство пользователя

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Appendix D. Glossary
61200212L1-1 DSU IQ User Manual D-7
permanent virtual circuit (PVC)
A frame relay logical link, whose endpoints and class of service are defined by
network management. Analogous to an X.25 permanent virtual circuit, a PVC
consists of the originating frame relay network element address, originating data
link control identifier, terminating frame relay network element address, and ter-
mination data link control identifier. Originating refers to the access interface
form which the PVC is initiated. Terminating refers to the access interface at
which the PVC stops. Many data network customers require a PVC between
two points. Data terminating equipment with a need form continuous commun-
ion use PVCs. See also data link connection identifier (DLCI).
ping
An internet protocol standard that provides loopback on demand for any device
in an IP network. One device "pings" another by sending a loopback request to
the device's IP address.
point-to-point
Type of communications link that connects a single device to another single
device, such as a remote terminal to a host computer.
remote configuration
A feature designed into ADTRAN DSU/CSU products that allow remote DSU/
CSU to be configured from a local DSU/CSU or VT 100 compatible terminal.
router
A device that supports LAN-to-LAN communications. Routers may be
equipped to provide frame relay support to the LAN devices they serve. A
frame-relay-capable router encapsulates LAN frames in a frame relay frames
and feeds those frame relay frames to a frame relay switch for transmission
across the network. A frame-relay-capable router also receives frame relay
frames from the network, strips the frame relay frame off each frame to produce
the original LAN frame, and passes the LAN frame on to the end device. Rout-
ers connect multiple LAN segments to each other or to a WAN. Routers route
traffic on the Level 3 LAN protocol (e.g., the internet protocol address). See also
bridge.
service
The provision of telecommunications to customers by a common carrier, admin-
istration, or private operating agency, using voice, data, and/or video technolo-
gies.