Abstract: The present invention provides a high switching capacity network device in one telco rack including both physical layer switch/router subsystems and an upper layer switch/router subsystem. Instead of providing a single physical layer switch/router subsystem, multiple physical layer switch/router subsystems are provided. Segmenting the physical layer switch/router into multiple, for example, four, subsystems better utilizes routing resources by allowing etches for the physical layer subsystems to be moved away from the center of the mid-plane/back-plane of the network device. Moving the physical layer subsystem etches away from the center of the mid-plane enables the network device to include an upper layer/switch router subsystem with etches toward the center of the mid-plane.

Abstract: The invention provides a method for fault isolation in a computer system, such as a network device. The method calls for providing a plurality of modular processes, and forming groups, based on hardware in the computer system, of one or more of the plurality of modular processes. A fault within a group is detected, and recovery from the detected fault is accomplished without affecting processes or hardware in other groups.

Abstract: The present invention provides a method and apparatus for supporting multiple redundancy schemes in a single network device. In one network device, various redundancy schemes are supported including 1:1, 1+1, 1:N, no redundancy or a combination of redundancy schemes. In addition, the redundancy scheme or schemes for physical network device cards (i.e., universal port cards) or ports may be different from the redundancy scheme or schemes for forwarding network device cards. For example, a network manager may want to provide 1:1 or 1+1 redundancy for all universal port cards and/or ports but only 1:N redundancy for each N group of forwarding cards.