http://www.rfc-editor.org/rfc/rfc1220.txt
RFC 1220: Point-to-Point Protocol extensions for bridging, F. Baker1991-04-01T23:00:00-00:00This document defines an extension of the Internet Point-to-Point Protocol (PPP) described in RFC 1171, targeting the use of Point-to- Point lines for Remote Bridging. [STANDARDS-TRACK]