VOIP (Voice Over Internet Protocol)

What is voice-over-internet protocol?

VOIP stands for voice-over-internet protocol. In general, it is a phone service over the internet. VOIP enables traditional telephone services to run more than a computer network. It refers to the transmission of voice traffic over an internet connection. It uses high-speed internet connection for phone service, instead of traditional copper lines of PSTN (public switched telephone network). Ip telephone is more versatile and enable the transfer of voice, data, and video to multiple devices including smartphones, laptop, and tablets at a very low cost. VOIP service providers do more than make calls. They handle outgoing and incoming call routing through existing telephone networks. Landlines and cell phones rely on the public switched telephone network (PSTN).

How voice-over-internet protocol Started?

VOIP was founded by the company VocalTech located in Israel in 1995 in order to create a way to save money on long-distance and international telephone charges. They developed a product called internet phone, an application that offered computer-to-computer voice calls using a microphone and speaker. With this internet phone, one user can use the same software to call another connected speaker and microphone. VocalTech began to be part of the company magic jack in 2010 and also joined several companies. There are numerous applications and software communication systems that use voice over IP, to offer complete used business communication solutions as well as internet telephony for personal use.

How does VOIP work?

To understand how VoIP works, let’s compare how it helps operate telephone phone calls. When you make a call using an analog line it establishes a dedicated connection between the two parties for the duration of the call. Voice over IP uses internet protocol, a necessary building block of the internet. Ip telephony is a great invention of the century-old telecommunication system. When you apply to generate phone calls above the internet. Your voice has to be encoded into digital data and this digital data has to be re-coded into the tone signal at the other end of the call. This coding process is achieved through codecs, which is short. The codecs ensure that the data is compressed, which means it moves faster and as a result, the quality of the call is better.

Differences to traditional phone lines.

Codecs are needed because, unlike traditional PSTN phone conversations that use analog data, VOIP uses digital signals. Codecs analog is used to encode sound data into digital signals that can cross the internet. When the digital signal reaches its target, it will be decoded once more in its analog shape, so the person on the line can hear the voice and understand it. Although the idea of digital voice data and codecs seems complicated just think of the process you would receive an email. Like any email, data has a destination. your voice code has been changed to run on the internet on the other hand the code is converted back into your voice so the person you are calling can understand what you are saying.

Some of the protocols used by VOIP are:

  • H.323
  • Session initiation protocol (SIP)
  • Session Description Protocol (SDP)
  • Media Gateway Control Protocol (MGCP)
  • Real-Time Transport Protocol (RTP)
  • Skype Protocol

Among these protocols, H.323 & SIP is the most commonly used protocol for VoIP.


H.323 is a VoIP standard for defining the components, protocols, and procedures. It provides real-time multimedia sessions including audio, video, and data transmission over packet-switched networks. Some services facilitated by H.323 include:

  • IP telephony
  • Videotelephony
  • Simultaneous audio, video, and data communications.


  • SIP acronym for session initiation protocol
  • Protocol to establish, modify and terminate multimedia sessions like IP telephony
  • All system that needs multimedia sessions is registered and provided a SIP address, much like IP address.
  • Facilitates multiparty multimedia sessions.

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