Switch fabric access scheduler

A system for providing access to a switch fabric comprising:

• a buffer configured to store a plurality of queues;
• and
• a queue scheduler associated with the buffer and configured to:
• receive an indication that a link included in a plurality of links to the switch fabric is next in order to be serviced by the queue scheduler;
• determine a current value of each of one or more link-specific scheduling state variables specific to the link;
• and
• use the link-specific scheduling state variables to select one of the plurality of queues as the next queue to be serviced by the link;
• wherein the queue scheduler is common to a plurality of links and is configured to use for each of the plurality of a links a corresponding set of one or more link-specific scheduling state variables specific to that link, with the result that queues are selected for each respective link in the plurality of links, by the queue scheduler common to them all, in a manner at least partly independent of each other link in the plurality.

A computer readable medium comprising, a computer program product for providing access to a switch fabric, the computer program product comprising computer instructions which when executed perform the following:

• receiving an indication that a link included in a plurality of links to the switch fabric is next in order to be serviced by a queue scheduling process common to the plurality of links;
• determining a current value of each of one or more link-specific scheduling state variables specific to the link;
• and
• using the queue scheduling process common to the plurality of links and the link-specific scheduling state variables to determine a queue to be serviced by the link;
• wherein the queue scheduling process common to the plurality of links is configured to use for each of the plurality of a links a corresponding set of one or more link-specific scheduling state variables specific to that link, with the result that queues are selected for each respective link in the plurality of links, by the queue scheduling process common to them all, in a manner at least partly independent of each other link in the plurality.