F-1
Cisco Secure ACS 3.0 for Windows 2000/NT Servers User Guide
78-13751-01, Version 3.0
APPENDIX
F

Cisco Secure ACS and Virtual Private

Dial-up Networks

Cisco Secure Access Control Server for Windows NT/2000 Servers Version 3.0
(Cisco Secure ACS) supports authentication forwarding of virtual private dial-up
network (VPDN) requests. There are two basic types of “roaming” users: Internet
and intranet; VPDN addresses the requirements of roaming intranet users. This
chapter provides information about the VPDN process and how it affects the
operation of Cisco Secure ACS.

VPDN Process

This section describes the steps for processing VPDN requests in a standard
environment.
1. A VPDN user dials in to the network access server (NAS) of the regional
service provider (RSP). The standard call/point-to-point protocol (PPP) setup
is done. A username and password are sent to the NAS in the format
username@domain (for example, mary@corporation.us). See Figure F-1.