glo-6 SmartSwitch 1800 4.0 User Guide, Rev 01IPLstands for “initial program load,” which is the loading into a node of the operatingsoftware on power-on or re-boot.IPXstands for “Internetwork Packet Exchange,” which is a Novell NetWare connec-tionless protocol that defines internetwork and intranode addressing schemes.LLANstands for “local area network,” which is a network operating over short distances athigh speeds.LCNstands for “logical channel number,” which is used as an identifier for a virtual circuitbetween a DTE and a DCE.Level 2is the link layer in the ISO (International Standards Organization) 7-layer OSI (OpenSystems Interconnect) reference model.Level 3is the packet layer in the OSI reference model.Line Interface Cardis a “daughter” card mounted in a SmartSwitch 1800, and containing the componentsthat support the two Voice ports.LLCstands for “logical link control,” which is the third layer in the three-layer ISO LANprotocol hierarchy. (The first two layers are Physical and MAC; MAC is described inthis glossary.) LLC is responsible for addressing and data link control.LLC2is a type of LLC that requires establishment of a connection before information can beexchanged. (The other type of LLC is LLC1, which does not require a connection.)Logical Channelis a logical link between node and subscriber, on which calls are sent or received. Thephysical line between devices may have a number of logical channels (also calledLCNs).Logical DCE/DTEsee “DCE” and “DTE.”LPDUstands for “LLC protocol data unit,” which is the unit of information exchangedbetween link stations in different nodes. The LPDU consists of destination serviceaccess point (see “DSAP”) and source service access point (see “SSAP”) addressfields, a control field, and (optionally) information fields.
