CASCD is the parent of all other processes that run for the lifetime of the region. If it detects they have died, it informs CASMGR and restarts them.
MFCS is the region communication component which handles the communication between clients and the Enterprise Server. There can be one or more communications servers per region depending on capacity needs.
MFCS is started by CASCD and contains the following service listeners:
It is represented by a TCTS control block in shared memory.
CASDBC is responsible for IMS DB support and is an optional component with one for every region. It is started by CASCD.