For each logon mode table associated with LUs that might be involved in a session with both APPN links and subarea virtual routes, specify an APPN Class of Service by adding the APPNCOS operand and a subarea Class of Service using the COS operand on the appropriate MODEENT macroinstructions. The subarea virtual routes use the Class of Service name coded on the COS operand, and APPN links use the Class of Service name coded on the APPNCOS operand. Using both the COS and APPNCOS operands enables you to use two different Class of Service names to represent the same Class of Service within the two subnetworks. This can be very useful as you migrate to APPN.

If neither the COS operand nor the APPNCOS operand is coded, the default Class of Service names (the unnamed Class of Service entry for subarea and the #CONNECT entry for APPN) are used.

If the COS operand is coded and the APPNCOS operand is not coded, the Class of Service name specified on the COS operand is used for both the subarea and APPN sessions. Therefore, when you want to use the same Class of Service name to represent identical Classes of Service in both the APPN and subarea networks, you do not need to code the APPNCOS operand when the COS operand is already coded. However, make sure that a corresponding APPN Class of Service definition exists in all network nodes. It is recommended that the architected standard APPN COS names be used.

If you code the APPNCOS operand and the COS operand is not coded, the unnamed Class of Service is used for the subarea session, and the Class of Service designated on the APPNCOS operand is used for the APPN session.