Modeling the Growth of Jumpers on the Main Distributing Frame

The Alain Distributing Frame (MDF) in a central office buildingserves as the connecting point between the cable outside and the equipment inside. Conventional M D F ' s are iron or wooden structures with terminal strips mounted on each side. The two sides are termed vertical and horizontal due to the manner in which the terminal strips are mounted. Cable pairs from subscribers' stations are terminated on the vertical side of the MDF, while line and trunk equipments are wired to terminals on the horizontal side of the frame. In order to provide service to a subscriber, it is necessary to connect his cable pair to the proper line equipment. A frameman makes this cross-connection by manually stringing a wire, called a jumper, between the corresponding vertical and horizontal terminals. These jumpers, which can easily be 100 feet long, are laid along horizontal shelves in the frame. As more and more jumpers are added to the frame, these horizontal shelves tend to become crowded. When the service to a particular station is discontinued, it is necessary to manually disconnect and remove the corresponding jumper. Unfortunately, disconnected jumpers are not always removed, which gives rise to dead jumpers in addition to the live jumpers. In the last few years, main frames which were originally conceived 1517