US Patent 11470010 Head-of-queue blocking for multiple lossless queues

A network element includes at least one headroom buffer, and flow-control circuitry. The headroom buffer is configured for receiving and storing packets from a peer network element having at least two data sources, each headroom buffer serving multiple packets. The flow-control circuitry is configured to quantify a congestion severity measure, and, in response to detecting a congestion in the headroom buffer, to send to the peer network element pause-request signaling that instructs the peer network element to stop transmitting packets that (i) are associated with the congested headroom buffer and (ii) have priorities that are selected based on the congestion severity measure.