ADTRAN 4175043L2, 4200659L1 gateway, host computer, idle code, in-band, local loopback LL

Appendix D. Glossary

FDL

Facility datalink. FDL bits provide overhead communication between the termi- nal equipment in ESF framing.

gateway

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

host computer

The primary or controlling computer in a multiple computer operation.

idle code

In a T3 circuit, an idle code consists of a sequence of 1100 over the entire pay- load bandwidth.

in-band

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

IP

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

LAN

Local area network. A privately owned network that offers high-speed communi- cations channels to connect information processing equipment in a limited geo- graphic area.

local loopback (LL)

A type of test used to verify the operation of the local terminal equipment, the CSU, and the connection between the two. The signal from the DTE is looped back by the CSU and is sent back to the DTE.

loopback

The technique for testing the processing circuitry of a communications device. May be initiated locally or remotely via a telecommunications circuit. Device being tested will echo back received test data. The results are compared with the original data.

61200659L1-1 MX2800 STS-1 User Manual D-7