I will be adding an Asterisk PBX to my office and had a basic question about the best way to incorporate the PBX and phones into my existing network. My current setup looks like this:

Would it be "best" to add another NIC to untangle and run the PBX on a separate subnet than my SBS/workstations? I was thinking that might make it easier to setup QOS for the PBX and I could also get a POE switch for the phones. One of the features I will be using will be a click2dial app that allows me to click on a contact in Outlook and it will dial the number. I was just wondering if having the computers and phones on a different subnet would cause any problems with that.

I'm running Untangle on a Dell SC440 and am using a dual port NIC and as well as another for the DMZ. I guess I should first check if there is even an available PCI slot...