Aastra 6757i User Manual page 4

What does it mean that our PBX is hosted?
Traditional PBX services depend on equipment located on the customer's
premises. This means that your telephones require a connection to this
equipment on site.
With Racknine's hosted service the PBX is not located on site. It is located at
Racknine and accessed through the internet. This means that telephones are
not tethered to your site. You can connect your phones anywhere there's an
internet connection. Operate from home just as you would in the office!
Transfer a phone call from your office in Edmonton to someone in your Calgary
office just as you would if they were in the same building!