Occasionally we hear people that want to connect an Asterisk to an IP Office. The below submission was compliments of Tek-Tips.com
IP Office setup:
1) Create a new SIP Trunk (SIP Licenses are required for this)
2) The only thing you fill in here is the IP address of Asterisks/TrixBox. Please note that this config is done anonymously, so I assume the two machines are either on the same LAN or connected securely via a VPN, I would not recommenced this setup if you are doing this over the internet.
IPSP IP : Asterisks IP
Prim Auth / Pass: