Relay

A relay is an intermediary server that carries a session when a direct connection between the two endpoints is impossible, for example behind strict firewalls or complex NAT.

Ubidesk prefers direct P2P and falls back to its regional relays when the network requires it. Relays carry the encrypted stream without being able to read it, with 99.9% availability (99.99% on Enterprise).

In practice

Relays also serve Wake-on-LAN: a relay on the same subnet sends the wake packet.