Operating notes for switch meshing

In a switch mesh domain traffic is distributed across the available paths with an effort to keep latency the same from path to path. The path selected at any time for a connection between a source node and a destination node is based on these latency and throughput cost factors:

  • Outbound queue depth, or the current outbound load factor for any given outbound port in a possible path

  • Port speed, such as 10Mbps versus 100Mbps; full-duplex or half-duplex

  • Inbound queue depth, or how busy a destination switch is in a possible path

  • Increased packet drops, indicating an overloaded port or switch

Pathshaving a lower cost will have more traffic added than those having a higher cost. Alternate paths and cost information is discovered periodically and communicated to the switches in the mesh domain. This information is used to assign traffic paths between devices that are newly active on the mesh. This means that after an assigned path between two devices has timed out, new traffic between the same two devices may take a different path than previously used.