APPC requirements detail

A fully qualified SNA network name is an identifier up to 17 bytes in length assigned to a SNA logical unit (LU) and represented as two symbols, each up to 8 bytes in length, separated by a period. For example:

USIBMNR.NRI41G00

The symbol preceding the period specifies the name of an SNA network and the symbol following the period specifies the name of an LU within that network. For ISPF C/S communications you need to know the fully qualified network name of an independent SNA LU type 6.2 associated with the workstation on which the ISPF WSA graphical user interface is to be displayed. The LU type 6.2 is required by the SNA communications software to support APPC connections to the workstation. for information about installation and customization of the SNA APPC software used on your workstation consult the documentation supplied by your software vendor. If you have already installed SNA APPC communications software on your workstation and you do not know the fully qualified network name of an independent SNA LU type 6.2 you can identify a candidate name as follows:

Table 1. Identifying a candidate name
If you have this SNA APPC workstation software	do this on the workstation
IBM® APPC Networking Services for Windows 1.00.02 (base product with CSD #2).	From the "IBM APPC Networking Services" program group select the icon for the Configure program item. Select the Step 1 pushbutton from the Networking Services Configuration window. The fully qualified local LU name for APPC communications will appear in the General Configuration window.

The fully qualified name of the independent LU selected for the ISPF WSA connection on the workstation must also be identified to VTAM® on the MVS™ system on which the ISPF C/S host agent will be invoked. The workstation independent LU can be identified to VTAM by one of these methods:

by dynamic definition by VTAM during session establishment
by CDRSC definition statements
by standard LU definition statements with LOCADDR=0 coded

The VTAM Network Implementation Guide and the VTAM Resource Definition Reference provide details on each method.

An LU definition must also be associated with the ISPF C/S agent on the MVS host to enable the connection to an ISPF WSA agent on a workstation. This LU must be made available to ISPF C/S by an APPC/MVS definition of a base LU to handle outbound connection requests from MVS to the workstation. The LU can be defined in one of two ways in the APPCPMxx member of the MVS parmlib data set by using a LUADD statement that includes one of these combinations of parameters:

The NOSCHED and BASE parameters
The SCHED(ASCH) and BASE parameters

If neither LU option is defined outbound session requests from the ISPF C/S agent on the MVS host will be rejected.

A VTAM application LU must be defined in VTAMLST to match the definition in APPCPMxx. Both the label of the APPL statement and the ACBNAME= parameter value must be identical to the value specified for the ACBNAME parameter on the LUADD statement for the APPC/MVS LU defined in MVS parmlib member APPCPMxx.

A logical connection called a session must exist between the LU associated with the ISPF C/S agent on the MVS host and the LU associated with the ISPF WSA agent on the workstation to support APPC communication. To establish a session the LU on the MVS host must send a set of session control parameters called a bind to the LU on the workstation. The parameters are selected based on a mode definition. The ISPF C/S agent on MVS uses the #INTER definition, which is located in the IBM-supplied default VTAM mode table ISTINCLM. The #INTER mode definition is also included among the default definitions supplied by the supported APPC communications software for workstations.

The VTAM node definition for the independent LU used by APPC Networking services for Windows cannot be the same VTAM node definition used for your native or emulated 3270 terminal support. A single node definition cannot be shared by APPC Networking Services for Windows and your 3270 terminal support. Likewise, if you are using a 3270 emulator on the Windows system on which you intend to use APPC Networking Services for Windows you must ensure that different local SNA service access point (SAP) addresses are used by the 3270 emulator and by APPC Networking Services for Windows.

To change the local SAP address for APPC Networking Services for Windows, select the icon for the Configure program item from the IBM APPC Networking Services program group. Select the Step 2 pushbutton from the Networking Services Configuration window, then select Advanced from the LAN Configuration window. The local SAP can be changed on the Advanced LAN Configuration window.