L

link service

The software component of SNA Server that communicates with the device driver for a particular communication adapter (802.2, SDLC, X.25, DFT, Channel, or Twinax).

local LU

In an APPC or CPI-C conversation, the LU on the local end. Contrast with partner LU and remote LU.

local program

In CPI-C, the program on the local end of the conversation. Contrast with partner program.

local TP

In an APPC or CPI-C conversation, the TP on the local end. Contrast with partner TP and remote TP.

locality

A Base and the components within it; that is, a SNA Server executable program. See also dynamic locality.

logical unit (LU)

(1) A type of network-accessible unit that enables users to gain access to network resources and communicate with each other. (2) A preset unit containing all the configuration information needed for a user, program, or downstream system to establish a session with a host or peer computer. SNA Server offers four types of LUs: 3270 LUs are used for 3270 terminal emulation; LU type 6.2 LUs are used for APPC; LUA LUs are used with programs written for the LUA interface; downstream LUs are used to allow downstream systems to connect to a host through a computer running SNA Server. On a computer running SNA Server, LUs are assigned to connections, and the connections and LUs work together to provide access to other systems on the SNA network.

Logical Unit Application (LUA)

A conventional LU application, or the interface that these applications use. LUA allows workstations to communicate with host applications using LU 0, 1, 2, or 3 protocols.

LPI address

Used to identify each end of a connection between two partners. It can have three components: L identifies the locality, P identifies the partner within the locality, and I identifies a logical entity within the partner. See also locality and partner.

LU 6.2

A protocol used by two TPs communicating as peers. LU 6.2 works in combination with node type 2.1 to provide APPC communications using independent LUs. LU 6.2 also works with node type 2.0 to provide APPC communications with dependent LUs.

LU alias

The string that identifies an LU to a TP. It can be up to eight characters long.

LU pool

A number of LUs, all of the same kind, that are made available as a group. A user, LUA application, or downstream system using the pool can get LU access as long as one of the pooled LUs is available. This provides for better access for multiple users, applications, or downstream systems in an SNA installation.

LU-LU session

The communication between two LUs over a specific connection for a specific amount of time. An LU-LU session is needed for two TPs to interact. One session can be used serially by many TPs. See also multiple sessions and parallel sessions.