This service facilitating peer-to-peer connections between RustDesk clients (viewers) and hosts (remote computers) when a direct peer-to-peer connection is not possible due to network configurations, firewalls, or other factors.
The relay server acts as an intermediary that helps establish communication between clients and hosts, ensuring a successful remote desktop session even in challenging network environments.
By default, the RustDesk Relay server listens on 21117 (TCP), 21119 (TCP).
When a RustDesk client wants to connect to a RustDesk host, it first attempts to establish a direct peer-to-peer connection using RustDesk ID/Rendezvous.
However, in some cases, direct peer-to-peer connections may not be possible due to network restrictions, such as NAT traversal issues or strict firewalls.
In such scenarios, the client switches to using the Relay server as an intermediary.
When a client and host cannot establish a direct connection, they both connect to this service
The client sends its data to the relay server, and the relay server forwards the data to the host.
Similarly, the host sends its data to the relay server, and the relay server forwards the data to the client.
This way, the relay server acts as a middleman, proxying the data between the client and host.
It helps with Network Address Translation (NAT) traversal.
It can handle scenarios where both the client and host are behind NAT routers, allowing them to communicate with each other through the relay server.
It can handle security and encryption to ensure that the data transmitted between clients and hosts remains secure and protected from unauthorized access.
Like RustDesk ID/Rendezvous, this service can handle dynamic IP addresses.
It allows devices to update their IP addresses with the relay server, ensuring that clients can always find the correct IP address of the host.