Glossary

Excess burst size ‹ (Be) The maximum amount of uncommitted data (in bits) in excess of Bc that a frame relay network can attempt to deliver during a time interval Tc. This data (Be) generally is delivered with a lower probability than Bc. The network treats Be data as discard eligible. See also committed burst size (Bc).

Exchange identification (XID) ‹ A specific type of basic link unit that is used to convey node and link characteristics between adjacent nodes. XIDs are exchanged between link stations before and during link activation to establish and negotiate link and node characteristics. They are exchanged after link activation to communicate changes in these char- acteristics.

FCC (Federal Communication Commission) ‹ The U.S. government agency that regulates the telephone industry.

FECN ‹ See Forward explicit congestion notification (FECN).

Firmware ‹ A computer program or software stored permanently in flash memory, read-only memory (ROM), programmable read-only memory (PROM), or stored semi-permanently in erasable programmable read-only memory (EPROM).

Forward explicit congestion notification (FECN) ‹ A bit set by a frame relay network to notify an interface device (DTE) that congestion avoidance procedures should be initiated by the receiving device. See also BECN.

Frame Relay ‹ A wide area networking connection to leased lines, providing multiple permanent virtual circuits or data link connections within the same physical access line.

Gateway ‹ Equipment that provides interconnection between two networks with different communications protocols. Two examples are packet assembler/disassemblers and protocol converters. Gateways operate at the 4th through 7th layers of the Open Systems Interconnection model. Contrast with bridge, router, repeater.

HDB3 (High Density Bipolar 3) ‹ A method of digitally encoding data on a link. A modified form of AMI used in Europe.

HDLC (High-level Data Link Control) ‹ A International standard communications bit oriented protocol developed by the International Standards Organization. HDLC manages synchronous, code transpar- ent, serial information transfer over a link connection.

host name ‹ A unique name that identifies each host machine on a network.

IEC ‹ International Electrotechnical Commission.

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