overlay network

term

networking

A network built on top of another one, whose links are tunnels across the network beneath it.

The one underneath is the underlay, and the split is the dominant pattern in modern infrastructure: route the underlay simply and reliably, and express everything the application wants in the overlay. The uncomfortable part is that a fault in the underlay appears in the overlay as something else entirely, so the layer that made the design tractable is also the layer that makes the diagnosis hard.

Also known as: overlay, underlay

Sources

An overlay network as a network built on top of another network, with its nodes connected by virtual links each corresponding to a path in the underlying network

← All glossary entries