RADIUS
This signature detects the Remote Authentication Dial In User Service (RADIUS), a client/server protocol that enables remote access servers to communicate with a central server to authenticate dial-in users and authorize their access to the requested system or service. By default, RADIUS uses UDP port 1812 for authentication, and port 1813 for accounting.
Available to all SRX running 12.3X48+
Available to all MX running 20.2R1+
Available to all vSRX running 20.3R1+