Abstract: A method for providing an early packet termination such that prior to the complete transmission of the number of cells specified in the first cell of a packet, a crossbar connection is released. The act of releasing the connection is triggered on recognition of an End of Packet bit (EOP) set in any cell of the stream. The feature can be enabled, for example, by a specific act of setting a register bit, connecting a pin to Vcc or ground or some other intentional act. The feature will default to the inactive state upon reset.

Abstract: A Fibre Channel switch is presented that tracks the congestion status of destination ports in an XOFF mask at each input. A mapping is maintained between virtual channels on an ISL and the destination ports to allow changes in the XOFF mask to trigger a primitive to an upstream port that provides virtual channel flow control. The XOFF mask is also used to avoid sending frames to a congested port. Instead, these frames are stored on a single deferred queue and later processed in a manner designed to maintain frame ordering. A routing system is provided that applies multiple routing rules in parallel to perform line speed routing. The preferred switch fabric is cell based, with techniques used to manage path maintenance for variable length frames and to adapt to varying transmission rates in the system. Finally, the switch allows data and microprocessor communication to share the same crossbar network.

Abstract: A routing module applies a plurality of routing rules simultaneously to determine routing for a Fibre Channel frame. Each rule independently determines whether the rule applies to the frame as well as a routing result for the frame. The routing result includes a port address, a zoning indicator, and a priority designation that can be used to route the frame over a virtual channel in an interswitch link. A selector chooses between the results returned by the rules. A component receives routing results specifying an ISL group and selects a physical ISL for the frame. An in-band priority determined by the content of the frame header can also be used in place of the priority designation in the routing result.

Abstract: A Fibre Channel switch is presented that tracks the congestion status of destination ports in an XOFF mask at each input. A mapping is maintained between virtual channels on an ISL and the destination ports to allow changes in the XOFF mask to trigger a primitive to an upstream port that provides virtual channel flow control. The XOFF mask is also used to avoid sending frames to a congested port. Instead, these frames are stored on a single deferred queue and later processed in a manner designed to maintain frame ordering. A routing system is provided that applies multiple routing rules in parallel to perform line speed routing. The preferred switch fabric is cell based, with techniques used to manage path maintenance for variable length frames and to adapt to varying transmission rates in the system. Finally, the switch allows data and microprocessor communication to share the same crossbar network.