VoIP phonewikipedia
A VoIP phone or IP phone uses voice over IP technologies for placing and transmitting telephone calls over an IP network, such as the Internet, instead of the traditional public switched telephone network (PSTN).
IP PhoneIP phonesEthernet-based phoneIP telephonesphoneIP desktop phoneIPVoIP phone serviceIP telephoneVoIP

Voice over IP

VoIPvoice over IPvoice over Internet Protocol
A VoIP phone or IP phone uses voice over IP technologies for placing and transmitting telephone calls over an IP network, such as the Internet, instead of the traditional public switched telephone network (PSTN). VoIP phones can be simple software-based softphones or purpose-built hardware devices that appear much like an ordinary telephone or a cordless phone.
In addition to VoIP phones, VoIP is also available on many personal computers and other Internet access devices.

Session Initiation Protocol

SIPsession initiation protocolSession Initiation Protocol (SIP)
Digital IP-based telephone service uses control protocols such as the Session Initiation Protocol (SIP), Skinny Client Control Protocol (SCCP) or various other proprietary protocols.
A SIP phone is an IP phone that implements client and server functions of a SIP user agent and provides the traditional call functions of a telephone, such as dial, answer, reject, call hold, and call transfer.

Power over Ethernet

power over EthernetPoE802.3at
This allows a single cable to provide both data connection and electric power to devices such as wireless access points, IP cameras, and VoIP phones.

Softphone

softphonesoft phonePC-to-PC calling
VoIP phones can be simple software-based softphones or purpose-built hardware devices that appear much like an ordinary telephone or a cordless phone.

SIP URI scheme

As the client may be a SIP phone or other device with just a numeric, telephone-like keypad, various schemes exist to associate an entirely numeric identifier to a publicly reachable SIP address.

Caller ID spoofing

caller ID spoofingspoofspoofed
If the caller name is sent with the call (instead of being generated from the number by a database lookup at destination) it may be configured as part of the settings on a client-owned analog telephone adapter or SIP phone.

Telephone

telephonephonetelephones
VoIP phones can be simple software-based softphones or purpose-built hardware devices that appear much like an ordinary telephone or a cordless phone.
The customer equipment may be an analog telephone adapter (ATA) which interfaces a conventional analog telephone to the IP networking equipment, or it may be an IP Phone that has the networking and interface technology built into the desk-top set and provides the traditional, familiar parts of a telephone, the handset, the dial or keypad, and a ringer in a package that usually resembles a standard telephone set.

Voice engine

voice engine
Voice engines handle the voice processing for an IP Phone system on a standard processor, compared to prior generations of systems which required dedicated, math-optimized digital signal processor chips.

Mobile phone

mobile phonecell phonemobile
There are several Wi-Fi enabled mobile phones and PDAs that have pre-installed SIP client software, or are capable of running IP telephony clients, including most smartphones.

Extension Mobility

extension mobility
The Cisco Extension Mobility feature, sometimes referred to as hoteling, allows a user to temporarily configure another IP telephone as his own.

Comparison of VoIP software

SIP Softphonesproprietary formats
Softphones are client devices for making and receiving voice and video calls over the IP network with the standard functions of most original telephones and usually allow integration with VoIP phones and USB phones instead of using a computer's microphone and speakers (or headset).

Invoxia

Invoxia Triby
Invoxia designs and markets smart office phones which communicate with smartphones and hybrid consumer IP Phone and wireless speakers.

Communications in Japan

Communications in Japan § Telephone servicesJapanese telephone companycommunications
IP phone lines in use: 16.766 million (2007)

Brastel Telecom

Recently they have started to invest in IP phone technology through their FLiP and Basix services.

Web-based VoIP

web-based VoIPintegrated into a web page
Instead of using dedicated, hard-ware based VoIP devices, such as IP phones, analog telephone adapters, or integrated VoIP/Internet access routers, services are provided via a web page and the facilities of the user's computer or hand-held device for accessing and operating a locally attached head set, and microphone.

VzRoom

vzRoom
vzRoom is a software system developed by Manipeer Limited for multi-party video conferencing, media sharing and VoIP phone integration.

Softswitch

softswitchVoIP softswitchsoft switches
Although the term softswitch technically refers to any such device, it is more conventionally applied to a device that handles IP-to-IP phone calls, while the phrase "access server" or "media gateway" is used to refer to devices that either originate or terminate traditional "land line" (hard wired) phone calls.

Sipgate

sipgate
Customers were expected to use a client software or a SIP-compliant hardware (a VoIP phone or ATA) to access its services.

BroadVoice

Customers can make and receive phone calls using an ordinary telephone, IP phone, Softphone or an Android or iPhone cell phone via an application.

Simple Network Management Protocol

SNMPsimple network management protocolSNMP management system
Sometimes called network elements, the managed devices can be any type of device, including, but not limited to, routers, access servers, switches, cable modems, bridges, hubs, IP telephones, IP video cameras, computer hosts, and printers.

VoIP vulnerabilities

Hardphones (a.k.a. VoIP phone) are smart devices, they are more a computer than a phone, and as such they need to be well configured.

Home network

home networkhome networkingsmart appliance

Selsius Systems

Selsius designed an IP PBX system consisting of a line of IP phones, a server-based call control application - the Selsius-CallManager, a line of voice over IP gateways and voice applications including voicemail, an automated attendant console and a softphone.