What is VoIP Termination
The mysterious VoIP-PSTN link
The concept of VoIP is quite easy to understand. The Internet is data agnostic. It doesn't care whether the information sent over the wires is text, image data, voice, or movies. All that 's important is that the receiving client should understand the type of data and be able to handle it appropriately. Because of this, the Internet is home to a variety of applications that are limited only by the creator's imagination. One of those applications is VoIP.
If you think about it, VoIP is quite easy to understand. Just like people send emails to one another for free, they can talk to one another over the Internet for free. Instead of text, which emails use, just use voice data instead.
So far so good.
The problems arise when we want to use the Internet to talk to people who are not using the same technology. Most people still use the plain old telephone system - POTS - and connecting to them using the Internet is a challenge. How do we take data which travels on the Internet and place it on the telephone network which is an entirely separate entity? What tools are needed, whose permission is necessary, and how much does it cost?
It's immediately clear that putting VoIP data onto the telephone network is impossible without the cooperation of the carriers. After all, they own the whole set up and they're the ones who ultimately need to provide the tools which allow us to make the switch. Technically though, it's still possible to bypass them. A third party can receive the VoIP data, convert that data into the format required for making telephone calls and then use their own phone connection to send that data to any dialed number.
But if we need to do this on a large scale and in an efficient manner, we have to tie up with the telcos. This is indeed what Internet Telephony Service Providers (ITSPs) do. By entering into a contract either directly or indirectly with the telcos, they're able to route Internet calls onto the telephone network and this is what VoIP Termination really is.
The reverse is true as well - we need to integrate with the telcos to transfer PSTN calls onto the Internet. ITSPs then route that data to the small business VoIP phones of their clients.
VoIP Termination is a critical part of SIP Hosted VoIP Systems. It's the gateway that opens up VoIP to the world and makes it what it is today.