PFC — Priority Flow Control
How PFC actually works. The PAUSE frame, per-priority pausing, head-of-line blocking, the PFC storm failure mode, and how to configure headroom so PFC fires before drops happen.
ECN — Explicit Congestion Notification
How ECN marks packets at congested egress, how the receiver echoes it back, and how DCQCN turns ECN signals into NIC rate adjustments — before PFC has to fire.
DCQCN, Buffer Profiles, and Tuning at Scale
Putting PFC + ECN + DCQCN together. Real buffer profiles, field-tested values, the order to tune in, and the symptoms that tell you a knob is wrong.