Defining VTAM requirements (CMAS)

ACF/VTAM definitions are required to identify each CMAS used by CICSPlex® SM. This involves creating VTAM® application definitions and, optionally, cross-domain resource management definitions.

Note:
You may already have defined the VTAM requirements for a CAS (see Defining VTAM requirements (CAS)). The steps for defining the VTAM requirements for a CMAS are different.

To create VTAM application definitions and cross-domain resource management definitions for a CMAS, you must perform the following steps:

  1. Create a VTAM application definition for each CMAS you will be using.
  2. Define each CMAS as a cross-domain resource.
  3. Add the application and cross-domain resource definitions to the VTAM configuration list.
  4. Activate the definitions.
Notes:
  1. Before you perform these steps, be sure to specify the size of the VTAM buffers.
    • For the VTAM-to-NCP connection, specify
      • MAXDATA >= 4096
    • For the NCP-to-VTAM connection, specify
      • MAXBFRU * IOBUF >= 4096
      • MAXBFRU * UNITSZ >= 4096
    • For the NCP-to-NCP connection, specify
      • TRANSFR * BFRS = RUSIZE >= 4096
    The size specified should be 36 bytes less than the smallest MAXDATA value in any NCP through which the link may pass. The 36 bytes allow for the headers that are required for VTAM. For more information about the requirements for the VTAM-to-NCP connection, refer to the VTAM Resource Definition Reference manual for your level of VTAM. For more information about the requirements for the NCP-to-VTAM and the NCP-to-NCP connections, refer to the NCP Resource Definition Reference manual for your level of NCP.

    If you need help determining or modifying your VTAM buffer specifications, confer with the VTAM system programmer at your enterprise.

  2. Depending on your VTAM conventions, you may need to modify the procedures that are described in this section. Specifically:
    • Change references to the SYS1.VTAMLST library if you do not keep your definitions in the default VTAM list.
    • Modify the APPL and CDRSC statements if you want to add these statements to existing members, rather than create new ones.

Once CMAS is running, you can access CICSPlex SMand define VTAM to CICSPlex SM. (See Setting the VTAM APPLID for a CMAS.)

Step 1: Creating a VTAM application definition (CMAS)

To establish a VTAM application definition for a CMAS, either create a new member (major node) or access an existing member in the SYS1.VTAMLST library. Then add the following APPL statement:

          VBUILD TYPE=APPL
name      APPL ACBNAME=acbname,AUTH=(VPACE,ACQ,SPO,PASS),              x
               EAS=10,PARSESS=YES,SONSCIP=YES,APPC=NO,                 x
               VPACING=number

where:

name
Is a 1- to 8-character unique name.
acbname
Is the node name of this CMAS. This name must be unique within the domain. If you omit this parameter, the name of the VTAM APPL statement is used.
vpacing
Is the maximum number of normal-flow requests that another logical unit can send on an intersystem session before waiting to receive a pacing response. Start with a value of 5.

For example, to create a VTAM application definition for the CMAS on SYSA, you might create a member (APCMAS1) in the SYS1.VTAMLST library that contains the APPL statement:

          VBUILD TYPE=APPL
CMS1      APPL ACBNAME=CMS1,AUTH=(VPACE,ACQ,SPO,PASS),                 x
               EAS=10,PARSESS=YES,SONSCIP=YES,APPC=NO,                 x
               VPACING=5

The same type of definition is needed for each CMAS you use.

Step 2: Defining cross-domain resources (CMAS)

You should define cross-domain resources (CDRSCs) when:

To establish a CDRSC definition, you must either create a new member or access an existing member in the SYS1.VTAMLST library. In the new or existing member, specify the following CDRSC statement for each CMAS that you want to communicate with:

         VBUILD TYPE=CDRSC
name     CDRSC CDRM=cdrm

where:

name
Is the name you assigned to a CMAS in Step 1.
cdrm
Is the name of the MVS™ image previously identified as the cross-domain resource manager (CDRM).

For example, to allow the CMAS on SYSA to communicate with the CMASs on SYSB and SYSC, you might create the member CDRCMS1, in the SYS1.VTAMLST library, which contains the CDRSC statements:

        VBUILD TYPE=CDRSC
CMS2    CDRSC CDRM=VTAMB
CMS3    CDRSC CDRM=VTAMC

where VTAMB and VTAMC are the cross-domain resource manager names that are assigned to SYSB and SYSC respectively.

The same types of definitions are also needed for the CMASs on SYSB and SYSC. That is, for the CMAS on SYSB, you could create a member (CDRCMS2), which contains the CDRSC statements:

        VBUILD TYPE=CDRSC
CMS1    CDRSC CDRM=VTAMA
CMS3    CDRSC CDRM=VTAMC

For additional information about cross-domain resources, see the VTAM Resource Definition Reference manual.

Step 3: Updating the configuration list (CMAS)

If, in Step 1 or 2, you created new members in the SYS1.VTAMLST library, you must update the VTAM configuration list for each MVS image. When VTAM starts, it automatically activates the new members.

To do this, add the new member names to the end of the configuration list in the appropriate ATCCONxx member of the SYS1.VTAMLST library. To find the suffix of the ATCCONxx member:

To illustrate, the examples shown in Steps 1 and 2 assume that the members APCMAS1 and CDRCMS1 exist. To add these members to the end of the configuration list in ATCCONxx, you would specify:

APCMAS1,                                                           x
CDRCMS1
Note:
If you added the CMAS and cross-domain definitions to existing members, ATCCONxx should already contain these member names.

Step 4: Activating the major nodes (CMAS)

You can activate the definitions that are created in Steps 1 and 2 by either restarting VTAM for each system, or manually activating the definitions.

To manually activate a major node, you can issue the following commands, where name identifies a major mode that was created (or modified) in Steps 1 and 2:

To ensure that the major node has been activated, issue the command:

   D NET,ID=name

For example, to activate the member APCMAS1 and then ensure that it has been activated, you would issue the commands:

   VARY NET,INACT,ID=APCMAS1
   VARY NET,ACT,ID=APCMAS1
   D NET,ID=APCMAS1

The preceding steps need to be performed for each CMAS you may be using.

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