# Congestion

These counters reflect possible errors that indicate traffic congestion in the fabric.

When congestion or a packet that has seen congestion is detected, one of these counters is incremented and then depending on the issue reported, the packet must wait. In an extreme case, the packet may time out and be dropped.

The category is calculated as a weighted sum of the counters in the context of the utilization counters. With the exception of PortRcvFECN, the counters are all reported on the transmit side of the link. In addition, PortRcvBECN is only taken if the local node is an HFI. However, the counter could indicate a problem on either side of the link.