Point-to-Point Protocol (PPP) - (IETF RFC 1661, Standard 51, Obsoletes RFC 1548, Updated by RFC2153) encapsulate IP packets so that they can be sent over a dial-up phone connection, W. Simpson, Editor, July 1994
PPP LCP Extensions - (IETF RFC 1570, Updates RFC1548, Updated by RFC 2484) PPP defines an extensible Link Control Protocol (LCP) for establishing, configuring, and testing the data-link connection, for which this document defines several additional features, W. Simpson, January 1994
PPP LCP Internationalization Configuration Option - (IETF RFC 2484, Updates RFC 2284, RFC 1994 and RFC 1570) defines an LCP configuration option for the negotiation of character set and language usage, G. Zorn, January 1999
PPP Multilink Protocol (MP) - (IETF RFC 1990, Obsoletes RFC1717) method for splitting, recombining and sequencing datagrams across multiple logical data links, originally motivated by the desire to exploit multiple bearer channels in ISDN, but applicable to any situation in which multiple PPP links connect two systems, including async links, K. Sklower, et al, August 1996
PPP Vendor Extensions - (IETF RFC 2153, Updates RFC 1661 and RFC 1962), W. Simpson, May 1997