About the CSX400CSX400 and CSX400-DC User’s Guide 9WAN ProtocolsThis device supports the following WAN protocols over the WAN port:• Point-to-Point Compression Control Protocol (CCP) as defined by RFC 1962• Inverse Multiplexing (IMUX)• Dynamic Host Configuration Protocol (DHCP) as defined by RFC 1541• Network Address Translation (NAT) routing as defined by RFC 1631• Point-to-Point Protocol (LCP) as defined by RFC 1661• Point-to-Point Protocol (BNCP) as defined by RFC 1638• Point-to-Point Protocol (IPCP) as defined by RFC 1332• Point-to-Point Protocol (IPXCP) as defined by RFC 1552• Password Authentication Protocol (PAP) and Challenge Handshake Authentication Protocol(CHAP) under PPP as defined by RFC 1994• Point-to-Point Protocol Line Quality Monitoring (LQM) as defined by RFC 1333• Point-to-Point Protocol Multilink Protocol (MP) as defined by RFC 1717• Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI) as defined by Q.921/Q.931• Frame Relay Link Management Interface (LMI) as defined by ANSI T1.617 Annex D and ITUQ.933 Annex A• Frame Relay Data Encapsulation as defined by RFC 1490• Frame Relay Data Compression Protocol (DCP) as defined by FRF.9PPP is a data link layer industry standard WAN protocol for transferring multi-protocol data trafficover point-to-point connections. With this protocol, options such as security data compression, andnetwork protocols can be negotiated over the connection.Frame Relay is a packet-switching data communications protocol that statistically multiplexesmany data conversations over a single transmission link. Data compression allows Frame Relay tonegotiate compression over Frame Relay permanent virtual channels (PVCs).ISDN BRI is a switched Data Link layer control protocol which uses digital signaling to place acall into an ISDN network. Once the call is made, PPP is then used to transfer data.