ATA (Analog Telephone Adapter): A device that coverts analog voice signals to digital signals which can then be transmitted over the Internet. These devices, some having two FXS ports, which are standard telephone ports where a traditional telephone can plug in, and an RJ45 port for connection to the Internet, can be used to connect analog devices, as extensions to a VoIP system.
Attendant (Auto Attendant): An automatic response system, such as a voice presenting options, such as press 3 for sales, 4 for Billing, 5 for Support, etc. An attendant can handle incoming calls and direct them to the proper person, department or extension. (Attendants are different than IVRs in that Attendants direct callers to make a choice and then push that number on the phone, where IVRs (Interactive Voice Response) can use a voice response to direct the call.
Cloud Communications: Cloud, which refers to the Internet, Communications uses the Internet as a way to have users connect to host communications equipment such as a PBX at a remote location which then connect to other users allowing phone calls. Synonymous with hosted VoIP or Internet Phone Service.
Codec: A term that comes from the encoder/decoder or Compressor-Decompressor process used for software or hardware devices that can convert a data stream. Two VoIP codecs often used are G711, a non-compressed codec, and G729, a codec that uses compression to lower bandwidth requirements.
CPE (Customer Premise Equipment): Equipment that resides on premise, usually at or with a business or customer.
CTI (Computer Telephony Integration): Is the use of computers to manage telephone calls, allowing for automation possibilities which allows for integration of text and faxing and other services.
Data: Usually treated as a synonym for information, but when used as a description for network topology refers to all traffic other than voice.
Data Transfer Rate: The speed of travel of a given amount of data from one place to another.
DID (Direct Inward Dialing): A service that allows a company to allocate individual phone numbers to each person within its PBX business phone system. Calling that individual number will bypass other call treatments and go directly to the individual's phone.
DSL (Digital Subscriber Line): Phone technology that allows a broadband internet digital connection to be carried over existing copper phone lines, while still allowing the phone service to carry analog signals over the same line.
Echo Cancellation: Echo cancellation uses both hardware and software as a process of eliminating echo from voice communication, improving the quality of the call. Generally necessary because speech compression techniques and packet processing delays generate echo. Two types of echo exist, acoustic echo and hybrid echo. Echo cancellation improves voice quality in VoIP calls and also reduces the required bandwidth due to silence suppression techniques.
IP Phone: A phone that connects using Internet Protocol instead of more traditional analog lines. An IP phone is more computer like, allowing advanced feature sets and other software functionality. Typically these phones have two Ethernet ports, one for the connection back to the Asterisk phone PBX device and the other to the user's PC. The phone acts a switch allowing both to connect to the network through one wall connection.
IVR (Integrated Voice Response): An integrated software information system that speaks to callers and uses voice responses. The voice response will direct the system to route the call or choose the next response in the IVR tree. By using touch tone keypad entries to interact with the software, you get voice responses with real time data.
Latency: The time (usually measured in milliseconds) it takes data or voice packets to travel from one point on a network to another point.
LNP (Local Number Portability): The ability of a US telephone customer to retain (or "port") their phone number if they switch to another local telephone provider.
Packet Loss: During a transmission some of the data that is sent in packets are lost due to latency, congestion at a router or other network problems. Packet Loss is specifically problematic to VoIP and even a small amount can result in significant voice degradation in the quality of the voice.
PRI (Primary Rate Interface): Each T1 circuit contains 24 separate channels. A PRI reserves one channel to carry special signaling and other information such as Caller ID, etc. for the other remaining channels. PRIs allow for multiple DIDs to be directed to individual phones once they reach the phone system.
PSTN (Public Switched Telephone Network): The traditional telephone network which uses pairs of copper wire to carry analog signals or digital T1 signals carrying multiple channels.
QoS (Quality of Service): QoS refers to a network system's ability to sustain a given service at or above its required minimum performance level. With VoIP this pertains to prioritizing voice data, usually RTP packets, over other services like Internet surfing, email, etc.
RJ-11: The typical 4 or 6 wire connector used to connect telephone equipment.
RJ-45: An 8 wire connector used to connect Ethernet connections in computers, routers, and other Internet devices.
Soft Phone: IP telephony software that allows end users to send and receive calls over their computer or a hand held PC device (PDA) over the Internet. Typically used in conjunction with a headset and microphone.
T1: A digital transmission link with a capacity of 1.544 Mbps using two pairs of normal twisted wires. T1s usually have 24 voice channels, each one of 64 Kbps.
T38: A recognized standard for sending fax transmissions over an IP network in real time mode. Faxing over VoIP can be a significant challenge and T38 sets standards that facilitate faxing over IP.
VoIP (Voice over Internet Protocol): The transmission of voice over the Internet as digital packets rather than the traditional circuit-committed protocols of the PSTN. VoIP uses real-time protocol (RTP) to help ensure the packets get delivered in a timely way.
WAN (Wide Area Network): A geographically disperse network that encompasses routers and other devices over a large area and can route that data to the proper endpoint.