ADTRAN TSU IQ+, 1204002L2 user manual Hdlc

Appendix D. Glossary

framing

A control procedure used with multiplexed digital channels (such as T1 carriers) where bits are inserted so the receiver can identify time slots allocated to each subchannel. Framing bits may also carry alarm signals indicating specific alarm conditions, cyclic redundancy checks (CRCs), and an out-of-band data channel in the case of an extended superframe (ESF) T1 link. In T1 terminology, a frame consists of 192 data bits and one framing bit.

gateway

A device which enables information to be exchanged between two dissimilar systems or networks.

HDLC

high level data link control. A generic link-level communications protocol developed by the International Organization for Standardization (ISO). HDLC manages synchronous code-transparent, serial information transfer over a link connection. See also SDLC.

host computer

The primary or controlling computer in a multiple computer operation.

in-band

Signaling (dialing, diagnostics, management, configuration, etc.) over the same channel used for data.

ingress

Frame relay frames leaving from an access device in a direction toward the frame relay network.

interface device

Provides the interface between the end device(s) and a frame relay network by encapsulating the user's native protocol in frame relay frames and sending the frames across the frame relay backbone. See also encapsulation and frame-relay- capable interface device.

IP

internet protocol. A protocol which provides for transmitting blocks of data between hosts identified by fixed-length addresses.

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