VoIP and 911: Is Your Agency Prepared?

摘要

Ever since the public was first made aware of the Internet, people and companies have been creating applications and systems to make our lives easier and make our spending more efficient. One of these systems is the adaptation of a technology called "Voice over Internet Protocol," or "VoIP," which allows voice to be transmitted over the Internet as a digital signal hidden in the network traffic rather than as a true electrical signal. The telephone companies have been using VoIP for years to connect their central offices, where the telephone lines from individual businesses and residences converge and are interconnected to other central offices or to a long-distance carrier. A switchboard operator used to manually "patch" the calls by plugging a cable from the subscriber into another plug for another subscriber or for a long-distance call. Electronic switches have since replaced the switchboard operator. These network lines use a data transmission method called "Internet Protocol" (IP), one of several ways data can be sent across a network. Web browsers and other Internet-capable computer programs also use IP to connect to servers throughout the Internet. In the past few years, simple "chat" programs, through which one computer user can send messages to another across the Internet, have expanded to include voice and video transmissions. The voice part of these chat programs uses VoIP technology to bring the voice across the Internet. This technology was then further advanced to allow VoIP devices to connect to the public switched telephone network (photo 1). Companies such as Vonage began making this available to the general public as an alternative to a traditional telephone system, sometimes referred to as POTS ("plain old telephone service"). Currently, there are more than 100 VoIP providers in the United States (Figure 1).