Using TTYs to dial 911 through VoIP service
It is not always technologically feasible for interconnected VoIP providers to automatically determine the location of their customers without their active cooperation.
Interconnected VoIP providers must obtain from each customer, prior to the initiation of service, the physical location at which the service will first be utilized.
Providers of interconnected VoIP services that can be utilized from more than one physical location must provide their customers a method of updating customer's location information.