Computer-controlled switching systems, such as telephone switching systems, like the No. 4ESS, are extremely complex. Such systems routinely require millions of bytes of program instruction and millions of bytes of data to function. When a system is lost, or is rendered inoperative, reassigning the tasks...http://www.google.com.au/patents/US6363498?utm_source=gb-gplus-sharePatent US6363498 - Method and apparatus to automatically back up switching system files
