VoIP Glossary of Terms

    Attendant (Auto Attendant) - An automatic response system, such as a voice presenting options such as press 2 for sales, 5 for Lisa, etc., which handles incoming calls and sends them to the appropriate phone or message.
    Attenuation - (also referred to as loss) is a term that occurs with any type of signal, (digital or analog) and refers to the reduction in the strength of the signal, which is natural consequence of that signal traveling over the specific medium for long distances.
    CDR Call Record Detail - Details about a specific call that includes duration, origination, destination, and billable information, as well as other pertinent information.
    Codec Coder-decoder - A device that typically uses pulse code modulation to transform analog signals into a digital bit stream and digital signals back into analog signals. In Voice over IP, the Codec defines the voice coder rate of speech for a Dial peer.
    CSU/DSU Channel Service Unit/Data Service Unit - A hardware device usually associated with a T1 that acts as an interface and converts data frames from a LAN to a WAN topology.

DID Direct Inward Dialing - A service that allows an enterprise to allocate individual phone numbers to each person within its PBX system.
Dual-tone multifrequency (DTMF) - The system used by touch-tone telephones. DTMF assigns a specific frequency (made up of two separate tones) to each key so that it can easily be identified by a microprocessor. This is basically the technology behind touch tone dialing.
Endpoint SIP or H.323 terminal or Gateway - An endpoint can Call and be Called. It generates and terminates the information stream.
Gateway In VoIP systems - a network device that converts voice and fax calls in real time from the public switched telephone network (PSTN) to an IP network.
Latency (Also called Delay) - The amount of time it takes a Packet to travel from source to destination. Together, Latency and Bandwidth define the speed and capacity of a network.

QoS (quality of service) - The ability of a network (including applications, hosts, and infrastructure devices) to deliver traffic with minimum delay and maximum availability.
Voicemail - Messages are stored on the phone companies server rather then at the answering machine. Voicemail provides the ability to check your message from any phone around the world by dialing in.
Voice Over IP (VoIP) - Is the process of transferring voice data over the public Internet. VoIP is a more efficient, low cost way of communicating with others. Over the next few years, analysts predict that the VoIP market will increase exponentially. There are a variety of different industry terms for VoIP, such as: VoIP, Internet Telephony, Broadband Telephony, IP Telephony, Digital Phone, etc.