Abstract: A layered bandwidth management system for transporting both STM and ATM traffic from customer circuit elements over a synchronous digital hierarchical (SDH (SONET)) transport network comprises a hybrid transport device for separately transporting STM and ATM traffic over separate first physical channels, the physical channels having fixed bandwidth allocations; a first bandwidth control device responsive to STM traffic contained in the first physical channel for directing STM traffic in fixed bandwidth allocations to a further destination; and, a second bandwidth control device responsive to ATM traffic contained in a separate first physical channel for switching the ATM traffic to a further destination, the second bandwidth control device capable of directing ATM traffic to the first physical channels for more efficient physical channel bandwidth utilization.

Abstract: A method and apparatus for the transparent, non-disruptable transfer of data, particularly multimedia data, through any packet-based network, such as an ATM network is provided. The method of the present invention includes the step of setting a primary path and a secondary path between nodes of a network, or of a network domain. Accordingly, when a switch or node establishes a Virtual Path (VP) to another switch with specified effective bandwidth, it also has an alternate VP that is available, although no bandwidth is actually used. The method of the present invention further includes the step of optimizing the available capacity of the system through management actions. For handling congestion and resource failures, the total effective bandwidth on each physical link is categorized in terms of idle capacity (unused or available), used capacity (for existing VPs), and spare capacity. When a resource failure occurs, the idle capacity is used for real-time switching of the VP and service is not disrupted.