VoIP Glossary from Broadview Networks 

Our VoIP experts help clarify the nuances of telephony.

Confused about a particular term or concept while learning about VoIP?  Allow the experts at Broadview to help clarify any question you have with our alphabetical glossary explaining the major themes in VoIP telephony.  If you still have questions, feel free to contact our team, we're happy to help!

What does VoIP Stand For?

VoIP stands for Voice Over Internet Protocol. In short, VoIP transmits voice data over the internet rather than a phone company. You will generally use VoIP through an ATA (see below) or an IP phone.

What are Analog Audio Signals?

These signals are used to transmit voice data over telephone lines.  This is done by varying or modulating the frequency of sound waves to accurately reflect the pitch of the sound.  The same technology is used for radio wave transmissions.

What is Asterisk?

A software implementation of a telephone private branch exchange; it allows attached telephones to make calls to one another and to connect to other telephone services such as the public switched telephone network (PSTN) and the Voice over Internet Protocol (VoIP) services.  Asterisk is open source and is often customized and rebranded.  People worldwide are familiar with the code - including hackers, which has become a major battle for competitors that use them.

What does ATA stand for? What is it?

ATA, or Analog Telephone Adaptor, is the hardware device that connects the conventional telephone to the Internet through a high speed bandwidth line.  It also provides the interface to convert the analog voice signals into IP packets, deliver dial tones, and manage the call setup.

What does an Auto Attendant do?

An auto attendant is an automatic response system that handles incoming calls and directs them to the appropriate phone or message through various options.  For example, a voice presents options to a caller such as press 2 for sales or press 5 for accounting.

What does bandwidth refer to?

Bandwidth is the amount of data that can be transferred from one point to another in a specified time frame.  It is usually measured in 1000 bits per second (kbps)

I’ve been hearing a lot about "BYOD" lately - What does it mean?

BYOD or Bring Your Own Device refers to the alternative practice of allowing employees to use a personally selected and purchased device within their company’s secure corporate network.  The practice usually refers to smartphones but can also apply to tablets, laptops, and other network connected devices.

What is call hunting?

A calling feature for inbound calls that will "roll past" a busy signal or try multiple numbers until the call is answered.

It seems like everything is in the cloud these days - What are cloud communications?

Internet-based voice and data communications where all telecommunication applications, switching and storage are hosted by a third-party outside of the group using them, and they are accessed over the internet.  Cloud telephony refers to voice services and more specifically the replacement of conventional business telephone equipment, such as a Private Branch exchange, with third-party VoIP Service.  

What is a codec?

Short for Code / Decode, it is software used by devices to convert or transform a data stream. For instance, at the transmitting end, codecs can encode a voice, video or data stream for easy transmission, storage or encryption. At the receiving end, they can decode the signal in the appropriate form for viewing or listening. They are most suitable for audio, videoconferencing and streaming media solutions.

What is direct inward dialing?

DID or direct inward dialing refers to a service with a company’s PBX system that allows an enterprise to allocate individual phone numbers to each employee.

What is dual-tone multifrequency?

DTMF is the standard system used by touch-tone telephones in which it assigns a special frequency, made up of two separate tones, to each key so that it can be easily identified by a microprocessor.

What is dynamic host control protocol?

DHCP, or dynamic host control, protocol, is a communications protocol that allows network admins to supervise and distribute IP addresses from a central point to each computer or device on a network.

How does find-me/follow-me work?

This feature allows calls to find you wherever you are, ringing multiple phones (such as your cell phone, home phone, and work phone) all at once.

In telecommunications, what does full duplex mean?

Full Duplex refers to the ability, in telephony and data communications, for both ends of a communication to simultaneously send and receive information without degrading the quality of intelligibility of the content.

What does hot desking mean and how can it save me money?

Hot desking is an organization tactic for offices that involves multiple workers sharing a single physical work station or surface during different times.  The “desk” aspect in the name refers to an office desk being shared by multiple employees on different schedules rather than each employee have their own desk.  This can allow a company to minimize the number of desks or number of phone lines, resulting in savings for the business.

Hot desking also refers to one employee being able to move from desk to desk, office to office and turn that phone into his/her own, including phone number, speed dials, feature preferences and voicemail. This enables employees to move freely both within an office and between multiple offices.

What is a phone system’s interaction voice response?

A phone systems’s IVR is an integrated software that speaks to callers through the use of menus and voice responses.  Callers interact with the IVR by using keypad entries to get voice responses with real-time data.

What does IP stand for?

IP is an acronym for Internet Protocol which defines the way data packets are moved between the source and destination.   On a more technical level, IP can be defined as the network layer protocol in the TCP/IP communications protocol suite.

What is my IP Address?

Your IP Address is a unique numerical label associated with each device participating in a network that uses IP for communication. The address serves two primary functions: network interface or host identification and location addressing. 

Is IP Telephony different than VoIP?

IP Telephony is the transmission of voice and fax phone calls over a packet-based IP data network.  IP Telephony is synonymous with VoIP.

What is an IP Phone?

An IP Phone (aka Internet Phone or SIP Phone or VoIP Phone) is a phone system handset that connects to the IP PBX over an IP LAN. Most often, IP phone look and function like standard legacy phone system handsets.  

What is jitter?

Jitter refers to a momentary fluctuation in the transmission signal that may result from an abrupt variation in signal characteristics, such as the interval between successive pulses. 

What does KBPS stand for?

KBPS is the acronym for kilobits per second and is used to define data transfer speed.

What does lag mean?

Lag indicated the extra time that data takes to travel from the source to destination and back again which can be caused by poor networking or by excessive processing. 

How does latency affect my VoIP system?

Latency, a synonym for delay, is a way of saying how much time it takes for a packet of data to get from one designated point to the destination. Latency is measure by sending a packet of data and once returned to the sender, that round-trip time is considered its latency. Any disruptions that cause that time to slow are considered lag.

What does messaging refer to in internet telephony?

This refers to any means of message store and forward.  This includes fax mail, voice mail and broadcast messaging. This horizontal application is the most popular of all other voice solutions. Messaging systems provide for the store and forward of "non-real time" communication. For example, a recorded voice message can be stored for later play back either locally or remotely, or a fax can be received and stored before it is re-transmitted to the ultimate recipient.

In terms of VoIP service, what is a packet?

A logically grouped unit of data. Packets contain a payload (the information to be transmitted), originator, destination and synchronizing information. The idea with packets is to transmit them over a network so each individual packet can be sent along the most optimal route to its. Packets are assembled on one end of the communication and re-assembled on the receiving end based on the header addressing information at the front of each packet. Routers in the network will store and forward packets based on network delays, errors and re-transmittal requests from the receiving end.

How can packet loss happen?

Packet loss can happen due to high network latency or due to overloading of switches or routers that are unable to process or route all the incoming data.

What does packet switching mean?

A means of economically sending and receiving data over alternate, multiple network channels. The premise for packet switching is the packet, a small bundle of information containing the payload and routing information. Packet switching takes data, breaks it down into packets, transmits the packets and does the reverse on the other end.

What is PBX and what does it stand for?

PBX stands for Private Branch Exchange and it serves as an in-house telephone switching system that interconnects telephone extensions to each other as well as to the outside telephone network (PSTN). A PBX enables a single-line telephone set to gain access to one of a group of pooled (shared) trunks by dialing an 8 or 9 prefix. PBXs also include functions such as least cost routing for outside calls, call forwarding, conference calling and call accounting.

How is peer-to-peer relevant to VoIP?

It is a type of network communication that allows file and data sharing between hardware and software without passing through the services of a server. P2P transfer is faster because P2P does not need a server to share files and data. 

What is the Primary Rate Interface (PRI)?

The Primary Rate Interface consists of 23 B-channels and one 64 Kpbs D-channel using a T-1 line and can have up to 1.544 Mbps service.   Typically, it is a dynamic circuit that delivers both voice and data, giving preference for voice.  When a channel is not carrying voice it is automatically allocated for data.

What does protocol refer to?

It is a convention or standard that defines the procedures to be adopted regarding the transmission of data between two computing end points. These procedures include the way the sending device should sign off a message or how the receiving device should indicate the receipt of a message. Similarly, the protocols also lay down guidelines for error checking, data compression, and other relevant operational details.

What does Quality of Service of a VoIP system mean?

The ability of a network (including applications, hosts, and infrastructure devices) to deliver traffic with minimum delay and maximum availability.

What exactly is my router?

A router is a network device that that handles message transfer between computers that form part of the Internet. The messages, which are in the form of data packets, are forwarded to their respective IP destinations by the router. A router can also be called the junction box that routes data packets between computer networks.

What does SIP stand for?

SIP stands for session initiation protocol which is a standard for initiating, maintaining, and terminating an interactive user session involving video, voice, chat, gaming, virtual reality, and more.

How does SIP relate to Phones?

A SIP phone is a telephone that uses the SIP (Session Initiation Protocol) standard to make a voice call over the Internet (for signaling (and uses RTP for media)). The SIP phones come with several value added services like voicemail, e-mail, call number blocking etc. There are (normally) no charges for making calls from one SIP phone to another, and negligible charges for routing the call from a SIP phone to a PSTN phone.

How does a softphone differ from a standard telephone?

A softphone is a software program for making telephone calls over the internet using a general purpose computer, rather than using dedicated hardware that would be needed with a standard telephone.  A softphone is usually used with a headset connected to the sound card of the PC, or with a USB telephone.

What is a switch when talking about VoIP?

A switch is a device that keeps a record of the MAC addresses of all devices connected to it and then channels incoming data from any of multiple input ports to the specific output port that will take the data toward its intended destination.

What does TCP stand for?

Transmission Control Protocol. The transport layer protocol developed for the ARPAnet which comprises layers 4 and 5 of the OSI model. TCP controls sequential data exchange in TCP/IP for remotely hosts in a peer-to-peer network.

Why is it called telephony?

Taken from Greek root words meaning "far sound", telephony is the discipline of converting or transmitting voice or other signals over a distance, and then re-converting them to an audible sound at the far end.

What exactly is VoIP?

The process of making and receiving voice transmissions over any IP network. IP networks include the Internet, office LANs, and private data networks between corporate offices. The main advantage of VoIP is that users can connect from anywhere and make phone calls without incurring typical analog telephone charges, such as for long-distance calls.

What exactly is a VoIP Phone?

A VoIP phone is one that uses the Internet to route voice calls by converting the voice data into IP packets and vice versa. The phones come with built-in IP signaling protocols such as H.323 or SIP that help in the routing of data to the right destination. A VoIP phone can also be a software application that is installed in the user's PC. In this case it is known as the Softphone. Also, the calls in this case have to be made from the PC, and not through a telephone instrument.

Sources: SIP Knowledge and VoIP Mechanic