SIP IP Phones & VoIP Phones

VoIP phones are devices connected to an IP phone system using LAN (Local Area Network) or the Internet. In comparison, traditional phones work over the PSTN telephone network, which comprises of physical copper wires. VoIP converts the standard telephone audio into a digital signal which can be transmitted over the internet and also converts incoming digital phone signals coming from the internet to standard telephone audio. A VoIP telephone can be a simple software-based softphone or a hardware device. A VoIP telephone allows users to make phone calls using VoIP (voice over internet protocol), to any softphone, mobile device or landline.

Simply put, a SIP Phone is a phone that uses the Open Standard “SIP” to set up and manage phone calls. Since these protocols are generically termed “VoIP” (voice-over-internet-protocol), these phones are also sometimes called VoIP Clients or VoIP Phones. The actual voice is carried over an IP-based network using another Open Standard called “RTP”.

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 transfer and call hold. SIP phones may be implemented as a hardware device or as a softphone.