Operations and Maintenance 1

There is a dichotomy within any complex computer system of two main parts: those that perform the application for which the system was built, and those that support the application functions but are not directly involved in them. Call Processing [Hamm2001] introduced the main application component of a telephone switching system, the HALF CALL (). The patterns presented here describe a number of functions that are necessary to switch telephone calls profitably, but that are not actually involved in seeing that a particular telephone connection or call is made.