Methods and devices are provided for controlling congestion in a network
such as a Fibre Channel network. According to some implementations, a
node within a network fabric detects congestion caused by an edge device
outside of the fabric and notifies the edge device of the congestion. The
edge device applies a congestion reaction mechanism in response to the
notification. In some implementations, the congestion reaction mechanism
is applied on a per-exchange basis, in order to mitigate congestion
caused by a particular operation.