A VoIP telephone or IP telephone is a hardware- and software-based telephone for Internet telephony that does not differ externally from a standard telephone. Depending on the constellation, a VoIP phone is a powered device( PD) that is supplied via Power over Ethernet( PoE) and connected to the IP network via a Digital Subscriber Line( DSL).
VoIP phones convert analog audio signals into digital data formats and transmit the data over the Internet. Several network components are required for operation. For example, the IP addresses are assigned to the VoIP phones via the Dynamic Host Configuration Protocol( DHCP), and a DNS system ensures that the corresponding devices are connected. Other protocols used for Internet telephony are the Inter-Asterisk Exchange( IAX), the Session Initiation Protocol( SIP) and the MediaGateway Control Protocol( MGCP). For VoIP, a terminal proxy server can serve as an interface for VoIP phones. It is a software program that runs on a signaling server and through which configuration, registration, and bandwidth control can be performed.
Feature set of VoIP phones
VoIP phones have a dial pad for dialing numbers and support a wider range of features than analog or digital phones for ISDN. These include video telephony, chat and team chat functions, text messaging, voice mail, call recording and logging, communication with headsets and other devices via Bluetooth, automatic answering machine, call forwarding and call recording, as well as some other features such as displays for date, time and caller ID, microphone and loudspeaker for hands-freecalling, keys for number storage, dialog keys for certain services, voice mailbox functions and voice quality selection. Furthermore, redialing and call forwarding, disconnect, toggle and transfer, automatic callback, call pickup or call forwarding, caller ID, call waiting and dialing a closed user group.
Just as with analog phones, there are also wireless VoIP phones that work with wireless fidelity(WiFi). With such phones, you can make calls worldwide via a hotspot, provided you have an account with a VoIP provider.