Switch fabric packet flow reordering

A network device comprising a plurality of fabric endpoints coupled to a switch fabric within the network device,

• wherein the plurality of fabric endpoints are configured to exchange cells across the switch fabric, and
• wherein an ingress fabric endpoint of the plurality of fabric endpoints is configured to:
• receive a plurality of packet flows for switching across the switch fabric to an egress fabric endpoint of the plurality of fabric endpoints for the packet flows;
• assign, based at least on a congestion status of each packet flow of the plurality of packet flows, each packet for each packet flow of the plurality of packet flows to one of a fast path for packet switching or a slow path for packet switching, wherein to assign each packet, the ingress fabric endpoint is configured to
• assign, based at least on the congestion status of a first packet flow of the plurality of packet flows being congested, packets for the first packet flow to the slow path for packet switching;
• and
• assign, based at least on the congestion status of a second packet flow of the plurality of packet flows being uncongested, packets for the second packet flow to the fast path for packet switching;
• and
• process, to generate a stream of cells for switching across the switch fabric to the egress fabric endpoint, packets from the fast path and the slow path to maintain a first-in-first-out ordering of the packets within each packet flow of the plurality of packet flows and to switch a packet of the first packet flow of the plurality of packet flows after switching a packet of the second packet flow of the plurality of packet flows despite the packet of the first packet flow being received by the ingress fabric endpoint before the packet of the second packet flow.

A non-transitory, computer-readable medium comprising instructions that, when executed, are configured to cause one or more processors of an ingress fabric endpoint of a plurality of fabric endpoints, the plurality of fabric endpoints coupled to a switch fabric within a network device and the plurality of fabric endpoints configured to exchange cells across the switch fabric, to:

• receive a plurality of packet flows for switching across the switch fabric to an egress fabric endpoint of the plurality of fabric endpoints for the packet flows;
• assign, based at least on a congestion status of each packet flow of the plurality of packet flows, each packet for each packet flow of the plurality of packet flows to one of a fast path for packet switching or a slow path for packet switching, wherein to assign each packet, the ingress fabric endpoint is configured to:
• assign, based at least on the congestion status of a first packet flow of the plurality of packet flows being congested, packets for the first packet flow to the slow path for packet switching;
• and
• assign, based at least on the congestion status of a second packet flow of the plurality of packet flows being uncongested, packets for the second packet flow to the fast path for packet switching;
• process, to generate a stream of cells for switching across the switch fabric to the egress fabric endpoint, packets from the fast path and the slow path to maintain a first-in-first-out ordering of the packets within each packet flow of the plurality of packet flows and to switch a packet of the first packet flow of the plurality of packet flows after switching a packet of the second packet flow of the plurality of packet flows despite the packet of the first packet flow being received by the ingress fabric endpoint before the packet of the second packet flow.