### Configuring for APPC communications at MVS

This section describes configuration for APPC at MVS. This configuration falls into two broad categories:

1. Configuring the APPC/MVS subsystem requirements (see MVS/ESA Planning: APPC Management)
2. Configuring VTAM, and possibly NCP, for APPC communications based on how workstations are connected (see VTAM Resource Definition Reference and NCP Resource Definition Reference)

Configuring the APPC/MVS subsystem is essentially independent of the type of network within which the workstations reside, and this section defines such configuring as it relates to VisualAge for COBOL. However, VTAM and NCP definitions vary depending on network characteristics and the manner in which the workstations are connected. Rather than attempt to address VTAM and/or NCP definitions for the many connections that are supported, we are restricting our description to APPC-related definitions for a 3745 attached token-ring LAN.

#### Prerequisites

Software and hardware prerequisites for APPC/MVS include:

- MVS/ESA V4.2 or later, or OS/390
- VTAM V3.4 or later
- NCP V5.2 or later
- DFSMS/MVS V1.2 or later

#### Terminology

Below is a table of standard APPC terms and the equivalent APPC/MVS terms. Some terms have no APPC/MVS equivalent, but instead are set in VTAM or NCP.

Standard Term | APPC/MVS Term
--- | ---
Network Name | NETID
LU Name | Name supplied for APPL definition in APPL major node
Partner LU Name | Name supplied for LU definition in major nodes defining each workstation
Local LAN Address | LOCADD (in NCP gen)
Adjacent LAN Address | DIALNO (on PATH definition in switched major node)

#### APPC/MVS configuration variables

#### APPC/MVS configuration overview

Configuring APPC/MVS requires the following:

- Add two members to SYS1.PARMLIB to define parameters for the APPC and ASCH subsystems, respectively.
- Define a TP profile and store it in the appropriate VSAM data set.
- Define a CPI-C side information entry for each participating workstation and store it in the appropriate VSAM data set.
- Define to VTAM an application major node for the APPC/MVS LU.
- Add APPC modes to the VTAM logmode table.

APPC configuration for the 3745 attached LAN in VTAM requires the following:

- Define a switched major node for the LAN.
- Identify PU definitions for each workstation.
- Identify a Type 2.1 (APPC) LU definition for each PU (or workstation).

APPC configuration for the 3745 attached LAN in NCP requires the following:

- Define the token-ring adapter in NCP.
- Define APPC session limits in NCP.

#### APPC/MVS definitions

Refer to your worksheet and replace the highlighted symbols in APPC/MVS definitions with the corresponding values defined in the worksheet.

1. Create Parmlib members

   Place two members (ASCHPMxx and APPCPMxx) in SYS1.PARMLIB. These two members have startup parameters for the two system components that make up APPC/MVS:

   - APPC - this component communicates with VTAM on behalf of APPC applications (see Figure 18).
   - ASCH - this scheduling component handles incoming requests for local transaction programs (see Figure 19).
2. Define the APPC/MVS LU in VTAM

   Refer to your worksheet and replace highlighted symbols in the VTAM APPL with corresponding values defined in the worksheet.

   Place the VTAM Definition in Figure 20 in a VTAMLST library (usually SYS1.VTAMLST):

3. Add APPC Modes to the Logmode Table

   Figure 21 has the recommended APPC modes.

#### Configuring to run as a server

Defining Transaction Programs:

1. APPC/MVS uses a TP profile to schedule an inbound request for a Transaction Program. VisualAge COBOL requires such a TP profile for the server. If this data set does not already exist, run this job to create a VSAM data set in which the TP profile can be stored.
2. The job in Figure 23 runs the APPC/MVS administrative utility to add a TP profile for DFM/MVS.

   Note: This might already have been done when the Data Facility Storage Management Subsystem/MVS (DFSMS/MVS) Version 1 Release 2 product was installed.

#### Configuring for debug tool to run as a client

Defining CPI-C side information:

1. Create VSAM Data set for CPI-C Side Information.

   The example job in Figure 24 creates the VSAM data set for CPI-C Side Information. It is necessary for subsequently defining side information entries allowing APPC/MVS to allocate sessions to an associated workstation. This data set is defined to APPC/MVS in the SYS1.PARMLIB member APPCPMxx. In the subsequent example, Figure 25 side information entries will be defined in the data set.

2. Side information entries are defined in the above data set by the sample JCL file ATBSIVSM.JCL.

#### Defining the 3745 attached LAN to VTAM

To define the LAN and its workstations to VTAM:

1. Define a switched major node describing the LAN.
2. Define a PU major node for a workstation.
3. Define the workstation APPC/LU.

Repeat steps 2 and 3 for each workstation on the LAN. Vary PARTNERLU, IDBLK, and IDNUM on each workstation.

The example in Figure 26 illustrates key VTAM definitions relating to APPC configuration for your LAN and an associated workstation. These definitions are possibly incomplete and their actual values are for illustration purposes only. Your VTAM administrator and the bibliography should be consulted to create complete definitions.

##### PU definition

Note that IDBLK and IDNUM are used to identify the workstation during VTAM's bind process.
for more information about NODEID.

As an alternative to IDBLK and IDNUM, CPNAME=PARTNERLU can be specified on the PU to identify the workstation during the bind process. In this case, NODEID does not have to be specified during workstation configuration.

PUTYPE=2 indicates that the workstation is capable of supporting independent LUs, which is a prerequisite for VisualAge COBOL.

For MODETAB and DLOGMOD, use the values defined on your worksheet. See VTAM Resource Definition Reference for additional values that you can use to define the workstation.

##### LU definition

PARTNERLU is the LU name that defines the workstation to VTAM. This value must be the same as the LU name that is specified during workstation configuration.
for more information about LUNAME at the workstation.

LOCADDR=0 identifies this as an independent APPC LU for the workstation that is being defined by the PU statement.

While no LUs are illustrated for 3270 emulator sessions, it is likely that emulators will be used with VisualAge COBOL remote debugging and they will be present in each PU and LU group that defines a workstation. See VTAM Resource Definition Reference for additional information on how to define APPC and emulator LUs.

#### Defining the 3745 attached LAN to NCP

The examples below illustrate sample NCP definitions relating to token ring and LAN APPC support. These definitions are possibly incomplete and their explicit values will vary for a given network. Therefore, these samples are for illustration purposes only. An NCP administrator should be consulted or see the references listed in the bibliography in order to create the appropriate definitions.

1. Define the Token-ring adapter in NCP

   A sample token-ring connection from NCP is in Figure 27

2. Provide for the use of host (APPC/MVS and/or CICS) LUs on the token-ring connection

   Once the token-ring is defined in the NCP, the only additional required parameter is NUMILU on the LUDRPOOL macro. An example is:

       POOL1    LUDRPOOL NUMILU=100,NUMTYP1=20,NUMTYP2=20

   In this example, the NCP can support up to 100 host (APPC/MVS or CICS) LUs that are connected via token-ring connections.

#### APPC/MVS system commands

Commands to Start APPC/MVS:

    START APPC,SUB=MSTR,APPC=xx
    START ASCH,SUB=MSTR,ASCH=xx

The `xx` is the identifier of the parmlib member. The default is 00.

Before you can start DFM/MVS, you must update the SYS1.PARMLIB member DFM00 and verify that the PROCLIB member DFM exists. Figure 28 shows the DFM00 parameters member, and Figure 29 shows the DFM procedure.

Before you start DFM/MVS, make sure that the APPC/MVS and PWS LUs are activated in ACF/VTAM and that APPC/MVS is started.

The following command starts DFM/MVS:

    START DFM,SUB=MSTR

Two address spaces are created: DFM and DFMCAS.

##### Monitoring APPC

Once APPC/MVS is activated, there are several commands that can be used to monitor APPC/MVS operation. A subset of these commands is shown below:

    DISPLAY APPC,TP,ALL
    DISPLAY APPC,LU,ALL
    DISPLAY ASCH,ALL

These commands provide information on APPC/MVS TPs, LUs, and scheduler operations, respectively.

Commands to Terminate APPC/MVS:

    C APPC
    C ASCH

For more information on APPC/MVS system commands, see MVS/ESA Planning: APPC Management.