I have a VPN connection at home to the work network, and I use an OptiClient. It works great. I started on V5 and now have V7 but didn't know there was any difference until now. I doubt you could assign a public IP address to a STMI, but the more likely solution would be to create a subdomain similar to voip.mycompany.com, and that subdomain can point at one of your company's static IP addresses that can then be routed in the firewall or other network appliance to be sent to the on-network address of the STMI card. If I rolled out this scenario I would dedicate one STMI for this purpose to minimize the affects on the system if someone were to get access to that board. I think that would be a workable solution. I don't know how much lag would be introduced by having the internet, nameserver and firewall touching everything on the way through. If you are using SIP, one STMI should be able to support 120 devices.