2.3 RADIUS Connection Layer

The RCL is a connection layer function that looks identical to the Diameter Connection Layer (DCL) from a signaling perspective. Both RCL and the DCL reside on the same DA-MP. RCL receives RADIUS messages and converts them to Diameter messages suitable for routing by DRL. DRL routing rules can be configured by the operator to forward the message to a RADIUS peer (through a RADIUS connection) or to another DSR (through a Diameter connection). RCL converts Diameter messages received from DRL to RADIUS before forwarding the RADIUS message to the peer.

RCL is designed to make RADIUS transparent to the DRL as much as possible. In order to make the RADIUS protocol completely transparent to the DRL, RCL must be RADIUS-transaction stateful for both ingress and egress transactions.