With VoIP service, telephone service including 9-1-1 service, will not be available during power outages unless the customer has special equipment. In addition, the phone will also not function if the connection to the internet is unavailable. This is important to keep in mind during an emergency, or when considering VoIP services.
Many companies around the world provide dynamic VoIP services. Dynamic VoIP service allows customers to use their phone anywhere in the world as long as they have a broadband internet connection. Special equipment is required to interface a phone with the internet. Typically, this equipment is small, lightweight, and very portable.
Dynamic VoIP's mobility is the driving factor in its popularity. It allows people to go anywhere in the world and allows family, friends, and business associates to call the phone as a local call, thus avoiding long-distance fees. This mobility also creates challenges when dialing 9-1-1
In a traditional phone system and Static VoIP, the phone is associated with a fixed location that does not move. New solutions to deliver the caller's location Information had to be devised that allows the customer to update their location. In addition, the 9-1-1 infrastructure currently in place does not support this type mobility.
Today, strides have been made to overcome these problems. However, in the past, it was traditionally the phone company’s responsibility to provide the address information of a customer to the 9-1-1 database. Due to the mobility, this responsibility now lies with the customer. If the customer does not ensure that the address information on file is accurate with their VoIP provider, calls for assistance when using 9-1-1 may be delivered to a PSAP thousands of miles away.
Additional information: http://transition.fcc.gov/voip/