http://www.rfc-editor.org/rfc/rfc2126.txt
RFC 2126: ISO Transport Service on top of TCP (ITOT), Y. Pouffary, A. Young1997-03-01T23:00:00-00:00This document is a revision to STD35, RFC1006. This document describes the mechanism to allow ISO Transport Services to run over TCP over IPv4 or IPv6. It also defines a number of new features, which are not provided in RFC1006. [STANDARDS-TRACK]