DRA
Diameter Routing Agent

The DRA enables PCRF (Policy and Charging Rules Function) discovery and selection as part of the PCC architecture. Essentially, if multiple PCRFs are available, the DRA will ensure an appropriate PCRF is initially selected and subsequently ensure that this PCRF is used for all future transactions associated with the subscriber. The DRA is also frequently termed the DRA (Diameter Routing Agency) or DSC (Diameter Signalling Controller). In all cases, the use of the DRA often goes beyond the PCC architecture and is often involved in general routing of all Diameter messages in the network.