glo-6 Smar tSwitch 1800 4. 0 User G uide, R ev 01
IPL stands for “initial program load,” which is the loading into a node of the operating
software on power-on or re-boot.
IPX stands for “Internetwork Packet Exchange,” which is a Novell NetWare connec-
tionless protocol that defines internetwork and intranode addressing schemes.
L
LAN stands for “local area network,” which is a network operating over short distances at
high speeds.
LCN stands for “logical channel numb er,” which is used as an identifier for a virtual circ uit
between a DTE and a DCE.
Level 2
is the link layer in the ISO (International Standards Organization) 7-layer OSI (Open
Systems Interconnect) reference model.
Level 3
is the packet layer in the OSI reference model.
Line Interface Card
is a “daughter” card mounted in a SmartSwitch 1800, and containing the components
that support the two Voice ports.
LLC stands for “logical link control,” which is the third layer in the three-layer ISO LAN
protoc ol hiera rc hy. (The fi rst two l a yers are Ph ys ical and MAC; MAC is de s cribed in
this glossary.) LLC is responsible for addressing and data link control.
LLC2 is a type of LLC that requires establis hment of a connection before information can be
exchan ged. (T he other ty pe of LLC i s L LC1, whi c h does not requ i re a conne c tion.)
Logical Channel
is a logical link between node and subscriber , on which calls are s ent or receive d. The
physical line between devices may have a number of logical channels (also called
LCNs ).
Logical DCE/DTE
see “DCE” and “DTE.”
LPDU stands for “LLC protocol data unit,” which is the unit of information exchanged
between link stations in different nodes. The LPDU consists of destination service
access point (see “DSAP”) and source service access point (see “SSAP”) address
fields, a control field, and (optionally) information fields.