IBM Systems Network Architecture

When I worked for USWest Communications I worked in the Regional Network Management Center where we maintained the corporate SNA network.

As is so often the case, it was IBM’s massive success in corporate networks that led to its downfall. It simply made too much money selling traditional network gear that had been developed to implement IBM’s breakthrough Systems Network Architecture (SNA). Although that architecture was introduced in 1974, it succeeded in becoming the common network architecture for virtually all of IBM’s customers.

At the heart of the SNA network was the beast known as the FEP — accurately describing its job as the Front End Processor. It was the size of a refrigerator, and when I first saw one in 1980, I noted that it was the last box in the computer room that still looked the way a computer was supposed to look — lots of flashing lights. It was quite complex (I know this, too, from firsthand experience) but it had two qualities that IBM probably cherished most: It was an indispensable part of the network, and it was expensive. The FEP was a cash cow.

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