I assume by that you mean it is on a private network behind a router, like a cable modem or public wi-fi?
There are two choices, either the user uses a VPN connection to connect to the corporate network, or you need to use ENC. There is a greenbook and a section in the implementation guide on ENC.
Steve McCormick, ITIL
CA Technologies
Principal Services Consultant
Tel: +1-731-676-4223
Stephen.McCormick@ca.com
<mailto:Stephen.McCormick@ca.com>