ADTRAN 1204002L2, TSU IQ+ user manual Pvc

Appendix D. Glossary

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.

PVC

permanent virtual circuit. A frame relay logical link, whose endpoints and class of service are defined by network management. Analogous to an X.25 perma- nent virtual circuit, a PVC consists of the originating frame relay network ele- ment address, originating data link control identifier, terminating frame relay network element address, and termination data link control identifier. Originat- ing refers to the access interface from which the PVC is initiated. Terminating refers to the access interface at which the PVC stops. Many data network cus- tomers require a PVC between two points. Data terminating equipment with a need for continuous communion use PVCs. See also DLCI.

red alarm

A red alarm is declared on detection of an LOS or OOF not caused by an alarm indication signal (AIS) that persists for two seconds.

remote configuration

A feature designed into ADTRAN products that allows remote units to be con- figured from a local unit 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 into 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 of each frame to pro- duce the original LAN frame, and passes the LAN frame on to the end device. Routers 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.

SDLC

synchronous data link control. A link-level communications protocol used in an IBM systems network architecture (SNA) network that manages synchronous, code-transparent, serial information transfer over a link connection. SDLC is a subset of the HDLC protocol developed by ISO.

61200275L1-1 TSU IQ+ User Manual D-11