Network Architecture Task Force: Backbone Architecture Working Model

1. Each building is connected to the central ATM switching fabric directly (a) or indirectly (b). Redundant links through other buildings would allow the backbone to "self-heal" in the event of a loss of connection with the central hub due to fiber breakage or switch failure. Building switches [A] would likely be OC3 (155 Mb/sec). Approximately 15 regional hubs would likely serve the campus adequately.

2. The central hub (composed of an ATM switch [A] and one or more routers [R]) is redundantly located in separate facilities. The loss of one central hub will cause traffic to be re-routed to the other. Central switch would likely be OC12 (622 Mb/sec).

3. An optional link inter-connects the two hubs.