The IPOffice can build a VPN tunnel between sites thru the internet. Each should have its own lines for 911 but could share one sites PRI for LD calls. Some of my customers also share local dialing from out of state because it bills by the minute not per call and can be cheaper. As of now IPOffice cannot SIP trunk to the CO but will be available late this summer. The site with the PRI could also use a partial voice/Data T1 and provide internet access for that site with its built in router and firewall if you don't need a full voice t1.