The PAUSE frame is meant to be sent by a station (host) to the switch (or vice versa) as a flow control mechanism, only for that port. Assuming the switch has at least some egress buffering, it shouldn’t result in propagation away from that switch port, to say the switch’s uplink port, unless the switch finds itself completely congested. Most hosts won’t have flow control configured at layer 2, instead relying on TCP congestion control. It is only useful when you have non-TCP type traffic, for instance fibre channel over ethernet, and you want to avoid packet loss and prefer to try force buffering upstream Reply