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VoIP Hacks

Switching to VoIP

Want to cut your phone bill in half?

VoIP—voice over internet protocol—has revolutionized local and long-distance phone service, enabling anyone with a high-speed internet connection to make calls for a fraction of normal landline prices. Plug in and get talking with tips on:

What VoIP is, how it works, and how to use it
How to assess the pros and cons of VoIP and decide whether it’s right for you
How to switch from traditional phone service to VoIP

What Is VoIP?

VoIP is an acronym for voice over internet protocol, a new standard for allowing voice transmissions over computer networks running internet protocols. In other words, VoIP is a technology that lets you make and receive telephone calls via the internet. VoIP is more versatile and less pricey than the traditional telephone system. Plus, it can work in conjunction with that system, meaning you can use most VoIP services to call traditional phones.

How VoIP Works

Since VoIP is easy to use, you don’t need to know how it works, though a basic understanding can be helpful. If you’d rather just learn how to use VoIP, skip to Types of VoIP Services.

How Traditional Phones Work

Traditional telephones use a method called circuit switching to connect phone calls over the PSTN, or public switched telephone network.

The Analog PSTN System

The original PSTN system—no longer in use—was entirely analog, which means it converted your voice into a continuous electromagnetic wave that traveled over a copper line until it reached the receiver on the other end of the wire. There, it converted the wave back into sound. A typical phone call in the analog PSTN system would work as follows:

You pick up your phone. A dial tone indicates that your line is connected to your local telephone carrier.
You dial a phone number.
The PSTN system connects your line through a number of junctions, called switches, to create a single continuous copper line that ends at the phone you’re calling.
The phone rings. The party you’re calling picks up.
Your voice is carried as an analog signal to your local telephone carrier.
The PSTN opens a two-way connection, called a circuit, between your phones. This connection allows both of you to talk at once and stays open until both of you hang up. No one else can use the connection until you stop using it.

Ultimately, this system was inefficient and expensive because one phone call would tie up an entire copper wire. For instance, three continuous copper wires would be needed for three people from New York to make three separate calls to Los Angeles.

The Digital PSTN System

The current PSTN system is more efficient and less costly than the original but is still very similar to the analog version. It still relies on circuits, and each phone line in the modern PSTN is still connected to its local carrier by a dedicated copper wire. However, most carrier centers are connected by fiber-optic cables that can carry of thousands of calls at once. Here’s what happens when you make a call using the current system:

See steps 1–5 of the analog PSTN system.
The carrier then digitizes your voice signal, meaning that it converts the signal into distinct bits of data made up of 1’s and 0’s.
The digital signal is sent among thousands of other calls through a fiber-optic cable until it reaches the local telephone carrier of the person you’re calling.
The local carrier converts the signal back to analog and sends it along copper wire to reach the person you’re calling. The circuit is complete once it reaches your party.
The circuit remains open for the length of the call.

On the current system, three phone calls from New York to Los Angeles could travel most of the way on a single fiber-optic cable because these cables have much more bandwidth, or data capacity, than copper wires. The current PSTN system is still inefficient, though, because maintaining a constant circuit between two phones for the duration of the call takes up a lot of bandwidth and requires a great deal of expensive equipment.

VoIP and Packet Switching

VoIP has transformed telephone technology by using a technology called packet switching to eliminate circuits entirely. A packet-switched call works like this:

See steps 1–5 of the analog PSTN system.
Your voice is converted immediately into digital data. The data is grouped in packets.
The packets are stamped with the IP address (a unique number given to every device connected to a network) of the phone to which they’re headed. They then are sent through the internet.
Rather than travel along a single dedicated line, the packets move through the internet on devices called routers. Each router receives the packet and sends it to the next router along the least trafficked data lines, until the packet reaches its destination. This process ensures an efficient use of bandwidth.
If you’re calling another VoIP phone, the data reaches that other phone directly over the internet.
If you’re calling an analog phone, the data travels along the internet until it reaches the local phone company of the party you’re calling, where it’s converted back to analog and sent out via the local phone lines.

By eliminating the need to establish a single dedicated connection, VoIP dramatically reduces the bandwidth needed for any telephone call. And because VoIP can travel over the traditional data network of the internet, VoIP companies don’t have to lay their own separate voice networks. This reduces both their costs and your costs drastically.

Acknowledgments & Disclaimer