DNHR application in the FTS-2000 network

Summary form only given. When AT&T bid on the US federal government's new private network called FTS-2000, it was clear that competition between service providers bidding on this contract would be intense. To win this contract, it was realized that this network would have to be robust, reliable, provide a wide array of services, and be very efficient. It was therefore decided to adopt a dynamic nonhierarchical routing (DNHR) traffic architecture, which had proved economical and successful in the AT&T public switched network during the mid-1980s. In this case DNHR had to be adapted to the eighteen 5ESS/sup TM/ switches which would form the backbone of the FTS-2000 network. The adapted routing strategy was called DFR, dynamic flexible routing, which like DNHR took advantage of diverse customer calling patterns over a wide geographical area in this nationwide network serving four time zones. Due to the substantial increase in the network load the planners realized the need for an agile, short-term planning tool adapted to the volatile FTS-2000 environment, and thus the system called PATTERNS was developed. PATTERNS incorporates the same network design algorithm used for DNHR, in which the efficiency of routing pattern changes often makes it possible to accommodate moderate new traffic loads and avoid adding new circuits altogether.