Can CA 7 r12/12.1 run in the same SYSPLEX (even same LPAR) with a prior releases. Can you mix releases of CA7ONL and ICOM?
CA 7 r12/12.1 is downward compatible with 11.x initialized CAIRIM modules and 11.x is upward compatible with r12/12.1 initialized CAIRIM modules. You can also run r12 CA7ONL communicating with prior release of ICOM or an r12 ICOM with a prior release of CA7ONL.
Note for r12.0 and 11.3 CA 7:
If the LPAR you are upgrading has a more than one CA 7 running AND there will be a mixture on this LPAR of 11.3 CA 7 and 12.0 CA 7 and you want to run CAS9 to upgrade to a 12.0 CAIRIM initialized environment for CA 7, apply r12.0 APAR RO78117 and r11.3 APAR R082582. If you leave the CAS9 initialized environment at r11.3, then the APARs are not needed. APAR RO78117 is needed when all CA 7's are to be initialized for r12.