VoIP Business Glossary

Here we will try to describe most common terms in VoIP business trying to avoid all technical slang. Only most useful terms will be described.

A

ANI - (Automated Number Identifier): A fancy way of referring to your telephone number. (Pronounced Ann’EE or Ay-En-I.)

API - application program interface, a set of routines, protocols, and tools for building software applications. A good API makes it easier to develop a program by providing all the building blocks. A programmer then puts the blocks together.

Asterisk - A very popular open source software allowing a standard Linux server to be converted into a feature rich telephone system, supporting both analog and VoIP calling.

ATA (Analog Telephone Adaptor) - A small device to convert the signal required by your traditional analog phone into a VoIP protocol allowing VoIP provided service to be used. Used to connect a standard telephone to a high-speed modem to facilitate VoIP and/or fax calls over the Internet.

C

CDR (Call Detail Record) - Information regarding a single call collected from the switch and available as an automatically generated downloadable report for a requested time period. The report contains information on the number of calls, call duration, call origination and destination, and billed amount.

Callback – in telecommunications, a callback (also written as call-back) occurs when the originator of a call is immediately called back in a second call as a response and then can enter destination to make a call. This way it is possible to save on call charges (caller calls cheaper).

Call Queue - A Call Plan feature allowing multiple calls to be placed on hold before being connected to an extension or set of extensions. The call queue can be designed to hold calls until an operator at one of the assigned extensions becomes available or provide the caller with the option to go directly to voicemail.

Calling Cards - Prepaid Calling Cards are useful for making long-distance telephone calls. You pay in advance for the calling service that you can avail anytime. Depending on the cost of the card you receive a specific amount of calling time. As you use the card, the minutes are reduced, until you have used up all the time on the card. You can make long distance or international calls from any telephone using such cards.

Class 5 Switch - The switching hardware used by local phone carriers that provides local phone services such as dial tone, emergency 911 service, 411 information service, and access to toll-free numbers and long distance carriers.

Class 4 Switch - The switching platform used by long-distance carriers geared toward finding the local carrier owing a dialed number, and routing calls to that carrier. They structurally differ from class 5 switches and cannot provide local carrier features.

Codec - Coder-Decoder algorithms for packaging and un-packaging the voice portion of a VoIP call so it can be transmitted over an IP network. Codecs are available using different algorithms, each allowing the call a different level of compression.

D

DID (Direct Inward Dial) - A phone number that can only receive inbound calls and is incapable of dialing outbound. Migrating standard phone numbers from a traditional, local phone carrier essentially converts them to DIDs, as all other service is stripped when the numbers are ported.

DOS Attack (Denial of Service) - A malicious hack whereby a stream of packets is directed at an IP address with the intent to overload the server and crash it and to deny services to a computer or network.

DTMF (Dual Tone Multi Frequency): The sounds you hear when pressing the digits on the keypad of your phone. They are called Dual-Tone because they actually consist of two separate tones to distinguish them from a normal human voice.

E

E.164 - The international public telecommunication numbering plan. An E.164 number uniquely identifies a public network termination point and typically consists of three fields, CC (country code), NDC (national destination code), and SN (subscriber number), up to 15 digits in total.

F

Fraud - The unauthorized access of a phone system. The fraud could be the result of someone taking a lineman’s butt-set and connecting to your phone line at the junction box (called clip-on fraud) or the result of the malicious hacking of a phone system for more aggressive PBX fraud.

G

G.711 - The industry standard Codec used to transmit uncompressed calls.

G.729 - The most aggressive codec in regards to the realized compression on the audio portion of the call while retaining a consistent and acceptable call quality.

H

H.323 - An ITU standard that lays down guidelines for real time voice and videoconferencing utilities on the Internet. The H.323 standard supports voice, video, data, application sharing and whiteboarding and defines media gateways for conversion to packets.

Hardphone: Any phone that has matter, takes up space, is used to send and receive phone calls, and isn’t simply software on a computer.

I

IP address - An address comprised of four numbers, each ranging from 0 to 255, and normally expressed with each number separated by a period (such as 192.168.2.100). IP addresses are used to route network traffic from sender to receiver. The IP address is a major component field of a VoIP packet and is used to map the VoIP telephone call to a specific telephone number. In a VoIP telephony call, both source and destination (caller and receiver) addresses are used to establish and maintain the VoIP call.

ISDN (Integrated Services Digital Network) - An out-of-band signaling protocol used in traditional telephony whereby the overhead of the phone calls is located on a separate channel from the audio portion of the call.

IVR system (Interactive Voice Response) - Complex telephone systems allowing incoming callers to reach their desired extension by responding to questions by either pressing digits on the keypad of their phone or speaking keywords.

J

Jitter - The variations in transmission latency that can cause packet loss and degraded call quality in VoIP calls.

L

LAN (Local Area Network) - A computer network that typically exists within a small geographic area such as an office or campus environment.

LCR (Least Cost Routing) - The rates for a multitude of carriers to which a company has access are programmed into a database enabling the phone system to route any call dialed over the carrier with the least expensive rate to that terminating location.

M

Maximum concurrent calls - The maximum quantity of calls you expect to have active with your carrier at the same time. This is sometimes translated into the maximum concurrent sessions with a VoIP provider establishing the ceiling for concurrent calls they will accept.

N

NAT (Network Address Translation) - A common way of hiding the IP addressed used within your LAN from the outside world. NAT translates public IP addresses visible in the public Internet to internal IP addresses used within your LAN. A NAT firewall protecting your LAN intercepts unsolicited data types entering it from reaching your internal servers.

NOC (Network Operations Center) - The main building or center where the troubleshooting hardware and technicians are located for a long-distance, local, or VoIP carrier.

P

PBX (Post Branch Exchange) - A more complex variety of phone system that generally provides a large quantity of features to include not only standard voicemail but also conference calling, call queues, and account codes. An in-house telephone switching system that interconnects telephone extensions to each other, as well as to the outside telephone network.

Postpaid - Type of payment, when client pays for services AFTER using them.

Prepaid - Type of payment, when client pays for services BEFORE using them.

PSTN (Public Switched Telephone Network) - The interwoven network of long distance and local phone service providers utilizing traditional telephony and a cascading array of carriers and underlying carriers that allows any phone in the United States to reach any phone in the world.

Q

QOS (Quality of Service) - An aspiration of LAN design whereby applications, users, and data flows are prioritized through resource reservation control mechanisms to maintain bit rate and reduce delay, jitter, and packet loss.

R

ROI - Return Of Investment - A performance measure used to evaluate the efficiency of an investment or to compare the efficiency of a number of different investments. To calculate ROI, the benefit (return) of an investment is divided by the cost of the investment; the result is expressed as a percentage or a ratio.

S

SIP (Secession Initiation Protocol) - An application-layer control protocol, a Signaling protocol for Internet Telephony. SIP can establish sessions for features such as audio/videoconferencing, interactive gaming, and call forwarding to be deployed over IP networks thus enabling service providers to integrate basic IP telephony services with Web, e-mail, and chat services. In addition to user authentication, redirect and registration services, SIP Server supports traditional telephony features such as personal mobility, time-of-day routing and call forwarding based on the geographical location of the person being called.

Softphone - Software-based applications that display a small dialpad on your computer screen. The mouthpiece and earpiece of a traditional phone are replaced with the microphone and speakers on your computer.

Softswitch (short for software switch) - An API (application program interface) that is used to bridge a traditional PSTN and VoIP by linking PSTN to IP networks and managing traffic that contains a mixture of voice, fax, data and video. Softswitches are able to process the signaling for all types of packet protocols. Softswitch is a software-based switching platform, which is opposed to traditional hardware-based switching center technology. Softswitches also are based on open systems, another difference between them and traditional proprietary hardware switching systems.

T

T.38 - A newer FoIP (Fax over VoIP) protocol.

Terminator - provider/company which sends call to it's final destination (callee).

Troubleshooting - The process of resolving call quality and completion issues by identifying the variables, isolating them, and proving them as clean or suspect. It is best if executed in a methodical manner whereby each subsequent test builds on information learned in previous tests.

Trouble ticket - A tracking tool used within carriers to record trouble issues and their resolution. They are generally referenced by a trouble ticket number.

U

URL - Universal Resource Locator such as www.msn.com is a string of characters used to identify a stationary resource on the Internet.

V

VLAN - A virtual LAN that acts like a physically separate network, despite the fact that it is riding on the exact same switches as your primary.

VoIP (Voice over Internet Protocol) - A collection of supporting protocols and software elements allowing voice phone calls to be executed over an IP-based platform.