An integrated corporate backbone providing packet and fixed-bandwidth services

A 100-Mb/s fiber-optic ring is discussed. It uses low-level time-division multiple access (TDMA) that permits division of the bandwidth into bands of 25 or 50 Mb/s capacity. These operate independently and may carry either Ethernet/802.3 frames or transparent T1 traffic. The system is examined in the context of integrated services networks, since it provides both packet-based and fixed-bandwidth services over a ring circumference ranging up to 100 miles. As such it is a precursor to metropolitan area networks that are now emerging. Applications and lessons learned are presented