A Diameter Signaling Router (DSR) is a signaling Network Element (NE) composed of OAM servers and Message Processors, and can include the Diameter Intelligence Hub.
The DSR can be deployed either as a core router that routes traffic between Diameter elements in the home network, or as a gateway router that routes traffic between Diameter elements in the visited network and the home network.
The DSR serves primarily as a Diameter Relay Agent to route Diameter traffic based on configured routing data.