http://www.rfc-editor.org/rfc/rfc6023.txt
RFC 6023: A Childless Initiation of the Internet Key Exchange Version 2 (IKEv2) Security Association (SA), Y. Nir, H. Tschofenig, H. Deng, R. Singh2010-10-01T23:00:00-00:00This document describes an extension to the Internet Key Exchange version 2 (IKEv2) protocol that allows an IKEv2 Security Association (SA) to be created and authenticated without generating a Child SA. This document is not an Internet Standards Track specification; it is published for examination, experimental implementation, and evaluation.