 The addition of 'T' in recent years stands for troubleshooting, and reflects its use in network operations environments.The term is used to describe the collection of disciplines generally, as well as whatever specific software package(s) or functionality a given company uses to track these things.Though the term, and the concept, originated in the wired telephony world, the discipline (if not the term) has expanded to other spheres in which the same sorts of work are done, including cable television and many aspects of Internet service and network operation.