Congestion notification in a multi-queue environment

An apparatus comprising:

• a switch circuitry comprising:
• at least one network interface and
• circuitry to:
• based on sharing of bandwidth of an egress port between a first traffic class, subject to congestion control based on utilization of a first queue associated with the first traffic class, and a second traffic class:
• based on a first level of the first queue associated with the first traffic class, cause a reduction in packet transmission rate of the first traffic class, wherein the utilization of the first queue is based on a drain rate of the first queue and a transmit rate from the egress port and
• based on a second level of the first queue and the second traffic class having available shared bandwidth, cause an increase in packet transmission rate of packets of the first traffic class, wherein the first level of the first queue is higher than the second level of the first queue.

A method comprising:

• at a switch:
• based on sharing of bandwidth of an egress port between a first traffic class, subject to congestion control based on utilization of a first queue, and a second traffic class:
• based on a first level of the first queue associated with the first traffic class, causing a reduction in packet transmission rate of the first traffic class, wherein the utilization of the first queue is based on a drain rate of the first queue and a transmit rate from the egress port and
• based on a second level of the first queue and the second traffic class having available shared bandwidth, causing an increase in packet transmission rate of packets of the first traffic class, wherein the first level of the first queue is higher than the second level of the first queue.

A method comprising:

• at a switch:
• based on received telemetry data from at least one switch:
• selecting a next hop network interface device from among multiple network interface devices based on the received telemetry data, wherein:
• the telemetry data is based on congestion information of a first queue associated with a first traffic class,
• the telemetry data is based on per-network interface device hop-level congestion states from at least one network interface device,
• the first queue shares bandwidth of an egress port with a second queue,
• the first traffic class is associated with packet traffic subject to congestion control based on utilization of the first queue, and
• the utilization of the first queue is based on a drain rate of the first queue and a transmit rate from the egress port;
• and
• causing transmission of a packet to the selected next hop network interface device.