Air Force base chooses FDDI for sensitive intelligence networks

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Air Force base chooses FDDI for sensitive intelligence networks



The U.S. Special Operations Command at MacDill Air Force Base in Tampa, FL, has installed a horizontal fiber cabling plant to support its local and wide area intelligence networks. The new network, operating under the fiber distributed data interface protocol, will provide personnel with unprecedented access to national and regional intelligence and imagery support in nearly real-time.

Contractor for the project was Annapolis, MD-based Telecommunications Systems. The staging area, network design conceptions and project installation--including the physical cabling plant and high-end electronics and software--were handled from the company`s Tampa office.

The company currently has a ratio of government to commercial projects of approximately 80 to 20. The goal is to bring that up to 50% within the next three years.

The economics of fiber and copper cabling plants has changed dramatically during the past few years. The gap in costs for installing fiber and copper is closing. FDDI hubs still cost more than copper alternatives, but as far as the cabling goes, copper and fiber are virtually at price parity. Even the costs of fiber network interface cards are lower, dropping from $500 to under $200 in the last few years.

Aside from reasonable costs, the Special Operations Command chose fiber to the desk primarily for security and bandwidth. The three Air Force Base networks have both Secret and Top Secret classifications. Fiber lends itself to these highly secure systems. It`s nearly impossible to tap without detection; also, fiber does not radiate electromagnetic energy, which rules out a variety of eavesdropping techniques. In addition, these particular local area networks include applications such as video, map-based graphics, and multimedia, where fiber`s high bandwidth shines. FDDI on a fiber medium is well-suited to these applications, as is asynchronous transfer mode, which is under consideration.

While this project is a military intelligence application with an emphasis on security, it could just as easily have been a commercial one. There are more and more fiber-to-the-desk systems--even fiber implementations of Ethernet and token ring--as costs drop and fiber loses its mystique.

The horizontal fiber cabling plant runs to 265 locations within the Special Operations Command headquarters. The wall plate for each location contains six fibers--one pair of fibers for each of three FDDI networks. Approximately 26 miles of multimode fiber were used. More than 100 workstations have initially been connected to one or more of the FDDI LANs. Many other workstations and personal computers are connected via fiber to a separate Ethernet system. On the user`s side of the wall, color-coded fiber jumpers terminated with either ST- or SC-style connectors, depending on the classification and media, run from the wall plate to the workstation.

From each user location, the fibers return "homerun" style to the directorate`s main computer room, terminating in a set of patch panels manufactured by AMP Inc., Harrisburg, PA. The long cable runs permissible with fiber eliminate the need for multiple communications closets. In the single communications room, jumpers connect the patch panels to MMAC Plus hubs manufactured by Cabletron Systems Inc., Rochester, NH. These hubs supply the FDDI networking protocol and create the networks` ring topology. The patch panels and networking equipment fit within five cabinets in the communications/computer room.

All fiber terminations for the cabling plants--at the back of the wall plates for user locations and within the communications room--are made with ST-style epoxyless fiber connectors. A project like this requires numerous cable terminations--in this case, 3168. To keep productivity high in bidding these jobs, Telecommunications Systems has standardized on mechanical crimp-on fiber connectors from AMP as the terminating method of choice. In 1992, the company found that it could install two Lightcrimp XTC connectors for every one of the hot-melt type. And with the crimp-on connectors, it is not necessary to carry ovens around and wait for the terminations to cool.

After the network was installed, testing was done to validate proper polishing techniques, measure actual decibel losses and ensure that the system stays within optical power budgets. The testing phase of this project was complicated by the requirement imposed by the Special Operations Command that the contractor could not use two-way radios to communicate between user locations and the communications room. Instead, the contractor employed a handheld optical test set that uses the fiber channels themselves for voice communications. This handheld unit incorporates dual power meters, dual optical sources and a voice headset.

Communications is the key

Half the battle in getting these projects up and going and running properly is communications regarding expectations of the customer and close working relationships with the suppliers. Not long ago, Telecommunications Systems was a small company that depended on AMP for technical advice. During this period, AMP offered advice on premises cabling technology and equipment alternatives to meet the fast-changing needs of Telecommunications` customers--and mutual cooperation continues.

The horizontal fiber cabling arrangement will serve the Special Operations Command for a long time. It essentially future-proofs the installation and eliminates the need to ever pull another cable again. That`s the beauty of these structured network systems. They are easy to maintain, permitting customers to quickly accommodate reorganizations, workstation moves and rearrangements. For example, if a person moves from one desk location to another, all the technician has to do is switch around some patch cords in the communications room. q

R.T. Davis is director, Southeast region, at Annapolis, MD-based Telecommunications Systems.Th Lw32370 18

In the communications room, jumpers connect the patch panels to Cabletron MMAC Plus hubs, which supply the fiber distributed data interface networking protocol and create the networks` ring topology. The patch panels and networking equipment fit within five cabinets in the communications/computer room.

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