What Data Transfer Technology Does VoIP Use?

Understanding how VoIP works can be either easy or difficult. To understand the basics, you merely need a generalized idea of the technologies at work. As you go deeper, you become aware of the complexity. This article introduces the reader to the complexity underlying VoIP after explaining it in general terms.

Basics of VoIP

VoIP uses the Internet to send your voice to another user. If the other person is using the same VoIP service, it's just like sending an email. Instead of text, voice data is transmitted. However, if the other person is using a regular PSTN phone line, the data has to be sent over a "VoIP gateway" which interfaces with the telephone lines. Unlike an email, this costs money and so making calls to regular phones is always more expensive than making a call to another person using VoIP.

Transferring Data using VoIP

For a long time, there was no standardized way of sending VoIP data to another person. Imagine for a moment that you have a Gmail Email ID. How would you feel if you could only send email to Gmail users and not to a person with say a Yahoo! ID? This isn't as strange as it seems. Take regular IM chat for example. You can only IM users on the same network and not your friends using another one. This is because of conflicting protocols.

Till a few years back, VoIP was in a similar situation. There was no way for VoIP users on different networks to call each other since they used incompatible protocols. The only way was to send the data over the telephone line - a waste of money and resources. However in recent years, everyone has started standardizing their VoIP services based on what we call the SIP Protocol. This development allows anyone to talk to anyone else no matter which VoIP service they use. It's revolutionized VoIP and is a shot in the arm for the industry.

Unlike normal phone lines, VoIP transfers data in packets using a technology called packet switching. Your regular phone uses analog circuit switching instead. Packet switching allows a single line to be used by many different users at the same time and this lowers the cost of VoIP and can even make it entirely free. As free as sending an email.

While we haven't reached that stage yet, the future hold great promise. With ubiquitous Internet and high Internet speeds, it's simply a matter of time before we look back at the days of the old telephone!