# References

For more information about the PPP protocol, consult the following resources:

- L2TP Proxy Authenticate Extensions for EAP—draft-ietf-l2tpext-proxy-authen-ext-eap-01.txt (December 2006 expiration)
- RFC 1332—The PPP Internet Protocol Control Protocol (IPCP) (May 1992)
- RFC 1661—The Point-to-Point Protocol (PPP) (July 1994)
- RFC 1662—PPP in HDLC-like Framing (July 1994)
- RFC 1877—PPP Internet Protocol Control Protocol Extensions for Name Server Addresses (December 1995)
- RFC 1994—PPP Challenge Handshake Authentication Protocol (CHAP) (August 1996)
- RFC 2153—PPP Vendor Extensions (May 1997)
- RFC 2246—The TLS Protocol Version 1.0 (January 1999)
- RFC 2615—PPP over SONET/SDH (June 1999)
- RFC 2716—PPP EAP TLS Authentication Protocol (October 1999)
- RFC 3032—MPLS Label Stack Encoding (January 2001)
- RFC 3579—RADIUS EAP (September 2003)
- RFC 3748—Extensible Authentication Protocol (EAP) (June 2004)

  | Note: IETF drafts are valid for only 6 months from the date of issuance. They must be considered as works in progress. Please refer to the IETF Web site at http://www.ietf.org for the latest drafts.