Agilent Technologies J3916A Manual do Utilizador descarregar pdf (Página 161)

Glossary

141

LAN (Local Area Network)

A general-purpose communications network that interconnects a variety of

devices within a limited geographical area. Two common LANs, IEEE 802.3 and

Ethernet, have compatible cabling requirements, and can co-exist on a common

installation, but have different protocols. A LAN might connect computers on

adjacent desks, within a building, or within several buildings of a campus. See

also extended LAN.

LAN cable

A short distance network (up to a few thousand meters) used to connect many

network devices using a communication standard. LAN cables come in many

types. For example, thick (10 mm) coaxial cable, thin (5 mm) coaxial cable, fiber-

optic cable, and twisted-pair cable.

LAP-F (Link Access Procedure, Frame-Relay)

HDLC derivative level 2 link protocol required by Frame Relay.

Layer

A level in the hierarchy of telecommunications protocols. Protocols in the higher

layers inter-operate with those in the lower layers.

LCI (Logical Channel Identifier) also called Combined LCN

The combination of the 4 LGCN and 8 LCN bits into a 12 bit virtual circuit

identifier field. The range is 0 to 4095

Leased Line

Permanent link in a data communication network provided by a commercial

communications supplier.

Leased Line

Permanent connection for private use within a data communication network

independent of the public switching and signalling equipment.

Line

T1 and E1 equivalent of DCE. The signal from the Central Office to the User.

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Agilent Technologies J3916A Manual do Utilizador Página 161