Articles
An in-depth view of functionality from the VPN Architect, written March, 1998.
Manuals
A recommended resource for planning the implementation of a VPN on AIX is Chapter 9 of A Comprehensive Guide to Virtual Private Networks, Volume III.
Select the book, System Management Guide: Communications and Networks (located under the System Management Guides icon) and click on the + sign. Select "Chapter 4, Internet Protocol (IP) Security."