What congestion avoidance should be used in network switches and routers?

Weighted Random Early Discard (WRED) should be configured as the congestion avoidance, or congestion management method. WRED gradually drops packets while considering IP precedence, as network devices become congested. This allows PCoIP protocol congestion management features to work to reduce the network footprint and help alleviate the congestion.  In most cases these adjustments will not be visible to users.  

Tail-drop should not be used since it creates large gaps in PCoIP packet traffic which will degrade the user experience or in the worst case, cause a session disconnection. 

Note: Tail-drop is the default for most network switches and routers.  

Note: Even with WRED configured and significant congestion can result in dropping all-incoming packets (tail-drop). Additional bandwidth for PCoIP protocol, or queue sizing adjustments may be required