US Patent 10389646 Evading congestion spreading for victim flows

A network switch includes switching circuitry and multiple ports. The multiple ports are connected to a communication network. The switching circuitry is configured to receive via the ports packets that are assigned respective Virtual Lanes (VLs), and forward each packet for transmission via a respective selected port, to queue the packets pending for transmission via a given port in multiple VL-dedicated queues, in accordance with the VLs assigned to the packets, to mark an outbound packet, pending for transmission via the given port, with multiple congestion indications that are indicative of respective congestion states of the multiple VL-dedicated queues of the given port, and to transmit the marked outbound packet via the given port.