Switching system service controller operating in a closed loop with call processor using subscriber-specific scheduling memories

A method of operating a switching system which comprises a switching network, a call processor for processing a call, executing instructions associated with the call and controlling the switching network to establish a connection depending on the executed instructions, a service module memory for storing a plurality of modules each containing programmed instructions for each service feature, and a plurality of service scheduling memories respectively associated with subscribers or groups of subscribers, each of the scheduling memories including a plurality of tables respectively associated with different events which may occur during the process of a call by said call processor, each of said tables comprising a plurality of entries for storing service features of different priorities, each of said entries giving an indication of presence or absence of a following entry for a service feature of lower priority to be executed next depending on a result of requested execution of instructions by said call processor, said entries of the table being arranged according to said priorities and accessible by an entry pointer, the method comprising the steps of:

• a) detecting one of events when the call processor is processing a call from a subscriber;
• b) retrieving a table from the service scheduling memory of the subscriber according to the detected event;
• c) accessing an entry of said table according to the entry pointer and retrieving a module from said service module memory associated with the service feature of the accessed entry;
• d) requesting the call processor to execute instructions of the module;
• and
• e) incrementing the entry pointer by one and repeating the steps (c) and (d) if a presence indication of a following entry is given in the entry accessed by the step (c) depending on a result of the execution requested by the step (d).