What Is a Logical Unit?
The SNA network consists of physical processors, called nodes, which are connected by physical data links. The SNA network also consists of logical processors, called logical units (LUs). An LU lets a user gain access to network resources (such as programs) and communicate with other users. LUs provide protocols that let users communicate with each other.
LU 6.2 is a particular type of SNA logical unit. LU 6.2 provides a connection between its users and network resources (often called transaction programs). The protocol that LU 6.2 provides is called Advanced Program-to-Program Communications (APPC).