Here are some common terms that are related to Voice over Internet Protocol (VoIP):
ATA, which means Analog Telephone Adaptor, is a device that permits the user to link to a regular telephone unit to his computer or directly to his Internet connection to allow the use of VoIP. Basically, it is a device that transforms the analog voice signal into digital format. With an ATA, connecting a regular phone to the Internet and then using VoIP technology to make phone calls is easy. You simply plug the cable for your phone to the ATA instead of plugging it into the wall socket.
Codec is the shortcut for encoder/decoder and it is primarily helpful for the transmission of large files. In short, it provides a way to compress data so that it will consume less time and resources when it is transmitted.
E911 is the shortcut for Enhanced 911 that extends the concept of emergency calls to include Internet voice and mobile phones. The 911 service makes use of this telephone number to make it easier for people to remember the number to call in case of emergency. It would be the dispatcher who receives the call who will alert the appropriate service to respond to the emergency.
Frame Relay is a technique that is commonly used in packet switching. It provides a fast and efficient way to transmit data over the Internet because it only makes use of precious bandwidth when it is required. This means that much more transmissions could be allowed along the thousands of data routes.
Interactive Voice Response or IVR is a kind of software that transforms voice commands and touch tones from callers into computer queries. This allows the telephone system to provide responses to questions from callers without the need for human intervention. For example, a caller may inquire about his bank balance. After the confirming the identity of the caller, the IVR program will access the database, get the information and use prerecorded messages along with the retrieved information to simulate the presence of a customer representative responding to a customer inquiry.
Lag is the time needed for a data packet to travel from the computer of the caller to the computer of the receiver. Since voice communications have to occur in real-time, lag should be minimized as much as possible.
Latency is the delay in the response of the system when a request for data transmission is made. This is usually only in nanoseconds but it is often used to evaluate the performance of the network.
Router is the device that is responsible for receiving and sending data packets while they are being routed through the network until they reach their destination. In the case of VoIP, the router usually treats the packets containing voice in the same way that it treats other forms of data.
Soft phone is the term used for the program that receives and transmits calls using a computer or PDA. There is no actual phone used but instead, a microphone and headset is commonly utilized.