SIP Call
Free Calls over the Internet
The majority of the population is so used to paying usage fees for their telephone services that calls between people using SIP protocol may be an eye-opening concept. But if you think about it, Voice over IP calls are not all that different from text-based chat sessions. Both forms of communication are simply packets of data sent from one IP address to another. If it’s all the same to your network, then how come IM sessions are always free and telephone calls are not?
One Key Difference between Old Telephone Systems and VoIP
Telephone calls, IM sessions, and video chats can all be broken down into two parts. There’s the signaling step, which refers to the initiation and termination of the communication session, and the media stream, which refers to the actual data being passed from one end to the other. Traditional telephone system infrastructure meant that the telephone carriers handled both the signaling and the media stream (the media stream costs significantly more to send than the signaling data). Since they handled the entirety of the communication session, a service charge was required, usually in the form of a pay-per-minute fee. If your call had to go through two carriers, then it was probably even more expensive.
With the emergence of Internet based services like business VoIP providers came a separation of the signaling process and the media stream. Now different parties can focus on different sections of the communication session, meaning that they can develop better services with a lower price tag to their customers.
Anatomy of a SIP Call
For example, let’s look at how a SIP call transpires for an OnSIP customer. After the number has been dialed, OnSIP handles the signaling step by sending a small packet of data to both parties to initiate the call. The cost of this data packet is so negligible that it is free to OnSIP users. If the call is to another SIP address, then the digitized voice data (the media stream) will be sent through the Internet carriers of the people on each end. Since they are already paying for their Internet service, there is no need to charge either of them for that call. This type of call should cost the people on each end absolutely nothing.
Free SIP calls with OnSIP
Whether you’re making a call to a SIP address or receiving one, it’s always free with OnSIP. If you’re dialing a number with a SIP address associated with it, OnSIP will automatically recognize it and handle the call, meaning that it will also be free. Calls within your OnSIP network, which are inherently SIP calls, can be handled on your own LAN, meaning that they do not go through the Internet. These calls will also cost you nothing.
