We need an IPsec/Racoon based VPN (many roadwarriors -> 1host). PSK/XAuth hybrid authentication. The immediate goal is to replicate the VPN processes of a Cisco 2811 under RHEL4/5 using ipsec-tools and racoon.
The roadwarrior devices are Avaya 96xx IP telephones. The single host is a Linux SIP Proxy with a public IP (there really is no destination private network for the VPN). The purpose of the VPN is to obviate the need for network address translation for certain VPN ready IP phones.
Replicable step-by-step set up procedures are required.