Defining SNA requirements for CICSPlex SM

You require ACF/SNA definitions to identify each CMAS used by CICSPlex® SM. You must create z/OS Communications Server application definitions and, optionally, cross-domain resource management definitions. There are a number of steps to perform to create z/OS Communications Server application definitions and cross-domain resource management definitions for a CMAS.

  1. Before you perform these steps, specify the sizes of the SNA buffers.
    • For the SNA-to-NCP connection, specify:
      • MAXDATA ≥ 4096
    • For the NCP-to-SNA connection, specify:
      • MAXBFRU * IOBUF ≥ 4096
      • MAXBFRU * UNITSZ ≥ 4096
    • For the NCP-to-NCP connection, specify
      • TRANSFR * BFRS = RUSIZE ≥ 4096
    Specify the size as 36 bytes smaller than the smallest MAXDATA value in any NCP through which the link might pass. The 36 bytes allow for the headers that are required for SNA. For more information about the requirements for the SNA-to-NCP connection, refer to the SNA Resource Definition Reference manual for your level of SNA. For more information about the requirements for the NCP-to-SNA and the NCP-to-NCP connections, refer to the NCP Resource Definition Reference manual for your level of NCP.

    If you require help determining or modifying your z/OS Communications Server buffer specifications, discuss with the z/OS Communications Server system programmer at your enterprise.

  2. Depending on your SNA conventions, you might have to modify the procedures that are described in this section:
    • Change references to the SYS1.VTAMLST library if you do not keep your definitions in the default z/OS Communications Server list.
    • Modify the APPL and CDRSC statements if you want to add these statements to existing members, rather than create new ones.
  3. Use the sample SNA APPL statements in the SEYUDEF library members, EYUDVTIA and EYUDVTIB. You can modify these samples to fit your requirements.