Emulex Design & Manufacturing Corporation

Terrence R Doherty

Bruce Gregory Warren

Carl Joseph Mies

William Patrick Goodwin

Thomas Phillip Ambrose

The attaching of labels to an OPEN frame and applying label switched routing to SAS expanders is disclosed to eliminate the need for large routing tables in SAS networks. A label stack is inserted into the OPEN frame by the initiator, prior to the OPEN frame being transmitted. Each label contains the egress port for a SAS expander in the transmit path. Each SAS expander to be participating in the connection reads the labels to determine the egress port to connect to and through which data is to be sent. The SAS expander marks its label invalid or discards it and forwards the OPEN frame to the egress port where the next SAS expander will look for the first valid label. The process repeats until the OPEN frame reaches the edge device, at which time all labels are discarded and the OPEN frame is forwarded to the end device.

Label switched routing in SAS expanders

A method for maintaining configurable and dynamically adjustable per-channel local port/bypass port access ratios in the multiple SOCs within an SPI-attached frame-based switch enclosure to improve the access fairness of devices upstream from the destination device is disclosed. A frame-based switch enclosure may include multiple SPI-attached SOCs, each SOC containing a plurality of ports, with one or more devices connected to each port and one virtual channel assigned to each port. Given a frame-based switch enclosure with N SOCs, the local port/bypass port access ratio for a particular SOC and a given virtual channel, where the particular SOC is M hops away from the SOC having a port corresponding to the given virtual channel and M&#x3e;0, is 1:(N&#x2212;M&#x2212;1), while the local port/bypass port access ratio for the SOC (and the given virtual channel) having the port corresponding to the given virtual channel (i.e. the SOC for which M=0) is 0:0.

Dynamically controlling fair access to a system packet interface attached switch enclosure

Embodiments of the present invention are directed to controlling device access fairness in frame-based switches by automatically and continuously counting the number of actively communicating devices connected to each port and the type of devices connected to each port, and adjusting fairness accordingly. During a sampling window, the number of active devices and the type of devices connected to each port is determined. At the start of each fairness window, a weighted number of slots are assigned to each port based on the number of active devices connected to each port and the type of devices connected to that port. Within a single fairness window, each port is able to provide device accesses to the frame-based switch in accordance with the number of slots assigned to that port.

Controlling device access fairness in switched fibre channel fabric loop attachment systems

A method is disclosed for maintaining a table of recent accesses for each port for use in predicting whether a request for data from a source device is likely to be sent to a high speed or low speed destination device. The table of recent accesses lists every source device attached to that port and the speed of the destination device with the most recent access to each source device. When an OPN primitive is received at the source port, the source device is identified and used with the table of recent accesses to predict whether the destination device is likely to be high speed or low speed, and ultimately whether to send data from the source device or reject the request.

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Costa Mesa, CA, United States of America

Terrence R Doherty