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COMMORDR parameter

The optional COMMORDR parameter determines the order in which communication methods (XCF, TCP/IP, and VTAM) will be tried in attempts by the local CAS to communicate with remote CASs.

This parameter uses the following syntax:


Specify the first letter of one or more communication methods (X, T, or V) in any order. Each specified method will be tried in the order that you specify. The first method that successfully establishes communication with a remote CAS will be used.

The default is XTV, which means that the local CAS will first attempt to communicate with remote CASs by using the Cross-System Coupling Facility (XCF). If that method fails, TCP/IP will be tried and, if that fails, VTAM will be tried.


  • Because VTAM communication will be attempted if XCF and TCP/IP communications are not successful, a V will always be included in the COMMORDR string, even if you do not specify it. For example, COMMORDR=XT is interpreted as COMMORDR=XTV.

  • To use VTAM for CAS-to-CAS communication, all participating CASs must have the necessary VTAM information defined for them, as described in Define cross-system communication.

  • To use XCF for CAS-to-CAS communication, all participating CASs must also include CONVXCF=Y (either explicitly or by default).

  • The SPCF=Y parameter is still accepted in the CAS startup procedure but is ignored. To use the Cross-System Coupling Facility (XCF) to communicate with other CASs in a sysplex, specify CONVXCF=Y and X on the COMMORDR parameter.

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