|
|
|
|
SNA Components Used for LU0 Communications, shows the SNA components used for LU0 communications.
An LU0 application uses a dependent LU of type 0 that communicates with the host system by means of the SNAP-IX node. There are three sessions between the SNAP-IX node and the host node, as follows:
The physical unit-system services control point (PU-SSCP) session, between the PU 2.1 and the host's system services control point (SSCP); this is used for controlling the PU.
The SSCP session, between the SNAP-IX LU and the SSCP; this is used for controlling the LU.
The LU session, between the SNAP-IX LU and the host LU; this is used for data transfer between the LU and the host application.
The LU0 API provides the application with access to the LU session only. Some SSCP control messages are used by the LU0 API in order to establish the LU session, for example sending an INIT-SELF RU at start of day, but access is limited. The LU0 API provides no access to the PU-SSCP session.
Each LU used by an LU0 application must be configured using the Motif administration program, the command-line administration program, or the node operator facility (NOF) API (for more information, refer to the SNAP-IX Administration Guide or the SNAP-IX NOF Programmer's Guide). In addition, the SNAP-IX configuration may include LU pools. A pool is a group of LUs with similar characteristics, such that an application can use any free LU from the group. This can be used to allocate LUs on a first-come, first-served basis when there are more applications than LUs available, or to provide a choice of LUs on different connections.
|
|
|
 |
|