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Up to 512 IPC channels (= 1024/2) can be used under 5.1.5.72 version
Up to 341 IPC channels (= 1024/3) can be used in 5.1.5.72 or later
In other words, since the OS semaphore resource value (semume) cannot be arbitrarily changed in AIX, only 341 or more IPC connections can be used in AIX equipment.