It is a USR modem and the system does not have internet access to log in remotely.
Pretty much any document for remote access configuration, like Cisco, Inter-Tel, HP Procurve, etc. for the USR will work as far as configuration goes...
The keys are to lock DTE speed to 9600, ignore DTR and flow control, and enable auto-answer, then connect a standard null modem cable to the modem.
We require customers to provide a static public IP address, even hotels, and none of them have had an issue with it, then use a cheap wireless router (Manhatten 300N Wireless Router) to connect the Mitel network to the internet through it, and port forward 2000 to the ICP. We even require this if picking up a SX200 ICP for maintenance only that we didn't install.