Hierarchical switching devices

A method of switching packets in a hierarchical switching device, the hierarchical switching device comprising a plurality of sub-switches forming a fully interconnected all-to-all network and wherein the sub-switches comprise internal input ports and internal output ports to exchange packets with other sub-switches within the fully interconnected all-to-all network, comprising:

• allocating to each internal input port of a particular sub-switch of the plurality of sub-switches a queue partition for each external output port of the particular sub-switch;
• receiving a packet at an external input port of a first sub-switch of the plurality of sub-switches, wherein the packet is to be routed to a particular external output port of a second sub-switch of the plurality of sub-switches;
• routing, by a switch controller, the packet directly from the external input port of the first sub-switch to the external output port of the second sub-switch using an internal output port of the first sub-switch and a queue partition of the second sub-switch that is for the particular external output port of the second sub-switch.

A non-transitory machine readable storage medium having stored thereon machine readable instructions to cause a computer processor of a switch controller to:

• allocate to each internal input port of a particular sub-switch of a plurality of sub-switches of a hierarchical switching device a queue partition for each external output port of the particular sub-switch, the queue partitions having independent packets flow relative to each other, and wherein the plurality of sub-switches form a fully interconnected all-to-all network and the sub-switches comprise internal input ports and internal output ports to exchange packets with other sub-switches within the fully interconnected all-to-all network;
• and
• in response to reception of a packet at a first sub-switch of the plurality of sub-switches that is to be routed to a particular external output port of a second sub-switch of the plurality of sub-switches, route the packet directly from the first sub-switch to the second sub-switch using an internal output port of the first sub-switch and a queue partition of the second sub-switch that is for the particular external output port of the second sub-switch.