The VIP Enterprise Gateway Validation server is a RADIUS-based authentication service for interfacing with the enterprise network infrastructure. VIP Enterprise Gateway uses RADIUS Password Authentication Protocol (PAP) as the authentication protocol. Using CHAP, MS-CHAPv2, PEAP-MS-CHAPv2, or EAP is not supported. Authentications could be rejected if PAP is not used.  Since RADIUS is stateless, the UDP protocol is a natural fit, as UDP is stateless, too.