| SNA Terms and Concepts |
| Basic SNA Concepts |
| Operating System) use LU 0. Current releases of these |
| products also support LU 6.2 communication, which is |
| the preferred protocol for new applications. |
| For information about the data streams used by SNA logical units, refer |
NOTE | |
| to Systems Network Architecture Technical Reference. |
| Control Points |
| |
| A control point (CP) is an NAU that manages network resources within |
| its domain, controlling resource activation, deactivation, and status |
| monitoring. The CP manages both physical resources such as links, and |
| logical information such as network addresses. |
| SNA defines the following types of network control points: |
| System services control point |
| On a type 5 node, the CP is called a system services |
| control point (SSCP). It manages and controls the |
| network resources in a subarea network. For example, |
| an SSCP can use a directory of network resources to |
| locate a specific LU under its control, and can establish |
| communication between two LUs in its domain. An |
| SSCP can also cooperate with other SSCPs to establish |
| connectivity between LUs in different subarea |
| domains. |
| The SSCP also provides an interface to network |
| operators at the host system, who can inspect and |
| control resources in the network. |
| Physical unit control point |
| On type 4 nodes and type 2.0 nodes in a subarea |
| network, the control point is called a physical unit |
| control point (PUCP). |
| Control point |
| On type 2.1 nodes, the control point provides both PU |
| and LU functions, such as activating local link stations, |
| interacting with a local operator, and managing local |
| resources. It can also provide network services, such as |
| partner LU location and route selection for local LUs. |
Chapter 1 | 35 |