Normally when you call 911 from your cell phone the police dispatcher will get your location from your gps and from the cell tower you are connected to. But with VoIP systems, the address has to be configured manually. This has a few main repurcussions.
Be sure to tell the dispatcher your location. Even though they should have received your office address, it can be important for them to receive more specific tips on how to best get to your location. This includes information like which internal office you are in.
If you call 911 from the Groundwire or Bria softphone, the police will assume you are located at your office. If you are not, be sure to alert them to your different location