http://www.rfc-editor.org/rfc/rfc3438.txt
RFC 3438: Layer Two Tunneling Protocol (L2TP) Internet Assigned Numbers Authority (IANA) Considerations Update, W. Townsley2002-12-01T23:00:00-00:00This document describes updates to the Internet Assigned Numbers Authority (IANA) considerations for the Layer Two Tunneling Protocol (L2TP). This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.