DETAILED DESCRIPTION The present invention described and disclosed herein comprises a method and apparatus for transporting Fibre Channel frames between attached devices.
The apparatus comprises logic which supports but is not limited to the following features: Transport of Class 1, Class 2 and Class 3 frames, Support for the Arbitrated Loop topology on each link, Support for Fabric point-to-point topology on each link, Route determination in frame arrival time, and Interconnection or Networking of Fabrics.
In one aspect of the invention, the apparatus comprises separate port control modules, one for each attached device, a central router module, a switch core module, a fabric control module and a brouter (bridge/router) module.
In the preferred embodiment, the port control modules are connected to the router modules by separate route request connections and separate route response connections.
Through this structure, route requests may be provided from the port control module to the router while simultaneously the router provides route request responses to the same port control module.
Preferably, a common route request channel is utilized.
Thus, apparatus is provided to return a route response to a previously requesting port while other ports are arbitrating and sending route requests to the centralized router.
More generally, this apparatus provides for reading resource requests from multiple requesters while at the same time returning resource grant responses to previous requesters.
The router of the subject invention includes many advantageous aspects.
In the preferred embodiment, the router includes multiple state machines arranged in series for pipeline operation.
Specifically, in the preferred embodiment of the router, a hardware finite state machine operates on the route request and a hardware finite state machine provides the route response.
Thus, in this embodiment, the router includes an input for receiving the output of the route request generator of the port control module, an output for sending a route request response to the route request response receiver in the port control module, a hardware finite state machine to receive the route request, and a hardware finite state machine to provide the route response, in combination with a route determination system
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