A VoIP phone or IP Phone uses Voice over IP (VoIP) technology for placing and transmitting telephone calls over an IP network, such as the Internet, instead of the traditional public switched telephone network (PSTN) such as Telkom.
Despite the difference in technology used with VoIP phone calls, dialing, talking on the phone and receiving phone calls is pretty much the same as is experienced with landline phones.
A VoIP phone or application may have many features an analogue phone doesn’t support, such as e-mail-like IDs for contacts that may be easier to remember than names or phone numbers, or easy sharing of contact lists among multiple accounts.
No particular type of VoIP phone is required for using VoIP services. IP-based telephone services use control protocols such as Session Initiation Protocol (SIP) which is supported by most VoIP provide