Internet, Email & Telephones > Email & Communication Services

Phone Calls Over the Internet?

By Lasa Information Systems Team

It has been possible for some time to make voice calls using your existing Internet connection. This article explores why organisations may want to do this, what equipment is needed, the various options, and limitations of the technology.

Why make phone calls over the Internet?

Organisations could be saving money on telephone calls.

Whilst you're connected to the Internet, you're already paying your Internet Service Provider (ISP) a fee for the privilege. It could really make sense for you to avoid paying extra phone charges by making your voice calls over the Internet. Proprietary messaging services and a standards-based technology known as Voice over Internet Protocol (VoIP or Voice over IP) mean that you can make voice calls over the Internet either completely free or for significantly less than the cost of a traditional phone call.

Organisations most likely to benefit from these cost reductions are those that need to make lots of long distance phone calls, particularly abroad. This includes organisations that work internationally, but could also apply to organisations with lots of staff working remotely in other parts of the country or abroad.

Small organisations that already have computers and an Internet connection, and where staff work from home because there is no office, could also benefit, even if they are just making local calls. Many organisations will already have much (if not all) of what they need to make use of the technology depending on which option they choose. Any extra software required is often free or very low cost. However there may be some extra costs for hardware and services which mean Internet phone calls won't be worth it for everyone. See below for more information.

What will you need?

In order to start making voice calls over the Internet you'll need:

• An Internet connection (preferably broadband, dial up can workOK with local calls but sound quality may be poor over long distances)
  
• A computer with sound card (usually required unless using some hardware phones)

You'll also need:

• A microphone and headphones (speakers produce feedback and echoes) OR
  
• An IP Phone which looks like an ordinary phone with a handset, buttons and cradle, but connects to an Ethernet (network) port on your router or hub OR

• A special adapter called a VoIP adaptor or ATA (AnalogueTelephone Adapter) that allows you to connect an ordinary phone to anEthernet port on your hub or router.

Finally you will need:

• Messaging software (e.g. MSN Messenger) or a software phone program (also called a softphone)

• An account with a VoIP service provider (or voice messaging service) 

What are the options?

There are several options for making voice calls over the Internet so let's look at each of them in turn:

Proprietary Messaging Software

Real time voice chat over the Internet is possible using proprietary messaging services. Popular services include MSN Messenger, Yahoo Messenger, AIM, Microsoft Netmeeting, and Skype. Proprietary messaging systems provide a relatively simple way of getting up and running quickly. The software is generally freely available at no cost, and easy to set up. Access to the basic service is also usually free. However there are some disadvantages:

• You can generally only chat computer to computer, and withusers of the same service (MSN Messenger users cannot voice chat withYahoo Messenger users for example). This usually means downloading andinstalling software for each voice messaging service you wish to use. However, developments like PhoneGaim (- messaging software that allows you to connect to most of these popular messaging networks through just the one piece of software, and to make calls to traditional telephones) may mean this becomes less ofan issue.
  
• Proprietary services tend to be Windows based - options for Mac, Linux and Unix users are pretty limited if available at all.
  
• Voice quality is OK but may not be great, particularly over long distances or when using a dial up connection to the Internet.

You will need to download and install the latest version of the software on each computer that you wish to make calls to or from. In addition each computer will need to have a sound card, microphone and headphones (or IP phone). You will also still need to set up an account with each messaging service you wish to use.

Voice over Internet Protocol (VoIP)

Many VoIP applicatiomns use SIP (Session Initiation Protocol - a standards-based protocol that gets round some of the problems associated with proprietary messaging services and offers greater flexibility). For example VoIP is operating system independent - you can use it on a Mac, Windows, Linux etc. Depending on the method used to connect, VoIP calls may not always be completely free. Even where there is a cost however, it is usually significantly less than calls made on a traditional telephone.

You usually connect through a VoIP service provider of which there are many examples including BT Broadband Talk. For more examples see the list of service providers at VoIP.org and VoIP-info.org/.

There are several ways VoIP calls can be made:

Computer to computer:

There is usually no charge forVoIP calls made from one computer to another (peer to peer). Each computer will need to have software telephone (often called asoftphone) installed. The software simulates a real phone, pullingtogether the computer's microphone, sound card, and Internetconnection. Many different companies offer free or low cost softwareand connection services. Examples include Skype and Xten.

Analogue Telephone Adapter (ATA):

An ATA converts a standard analogue telephone signal from a traditionalphone to a digital signal that can be sent over the Internet. With anATA you can connect your standard telephone to your computer via asmall adapter that plugs into your phone socket. The phone cable thenplugs into the ATA and you're ready to make VoIP calls using your telephone. Your computer will need to be switched on however. There maybe additional software to install but this is usually prettystraightforward. Many traditional phone companies including BT arestarting to bundle ATAs with their VoIP services.

IP Phones:

These look similar to traditional phones but plug directly into yourbroadband router (a device which sends data around networks includingthe Internet), rather than a traditional telephone socket. Theadvantage is that you can use a VoIP phone anywhere you have anavailable Internet connection and network port. Wireless IP phones arealso available and potentially allow users to make VoIP calls from anywireless hotspot. Costs for IP phones start at around £70.

USB Internet phones

These plug into an available USB port on your computer. Prices start at around £25.

So far the options described allow you to make calls to other people who subscribe to a VoIP service. But what if you want to make calls from your computer to users of traditional phones and no broadband connection? Well technology has an answer for this too …

Calls to ordinary telephones

VoIP services are also capable of interfacing with telephones on the traditional PSTN (Public Switched Telephone Network) so you can make calls to "real" telephones using your broadband connection. For example Skypeout allows you to make VoIP calls to ordinary phone numbers all around the world for a relatively small fee.

Many other VoIP Service providers offer similarly low cost services (see the links to service providers above for more information).

Some services only allow you to connect to PSTN phones but not receive real time voice calls from them to your computer, so check to make sure the service does what you need it to do before signing up.

Are there any limitations?

Although VoIP can mean costs savings and be more convenient for some users, it isn't quite ready to be a complete replacement for traditional PSTN phones. Drawbacks include:

• Dependent on your Internet connection - since VoIPuses the Internet, the ability to make calls will be affected by thequality, speed and availability of your Internet connection. Local calls may be feasible over a dial up connection but for long distancecalls to other countries you'll probably need broadband. Also if yourInternet connection is down, you will not be able to make or receiveVoiP calls.
  
• Power supply needed - if thepower goes down, your PSTN phone will normally continue working (unlessit's a cordless phone). With VoIP, no power means no telephone.
  
• Viruses, Internet worms, and hacking- because VoIP uses the Internet, it is susceptible to attacks from these quarters, although this is very rare. Work on solutions to counter this is ongoing.
  
• Underpowered computers- VoIP calls can be affected by other applications running on yourcomputer. So for example if you are chatting away on the phone and open another application that uses up your computer's processing resources, call quality will suffer or your system could crash completely in the middle of an important call.
  
• Calls to emergency numbers- problematic if the caller is not able to say what their geographical location is, since there is no real way of associating an IP address with a geographical location. It may not be possible to route calls to the nearest emergency call centre, and with some VoIP services you may not be able to make emergency calls at all.

More information

More information on VoIP, including hardware, software and service providers can be found on the following sites:

• VoIP.org - UK based site with information on VoIP including hardware, software reviews and a discussion forum
• How Stuff Works article  "How VoIP Works" - Detailed generally plain language explanation of how VoIP works
• VoIP-info.org WIKI - A reference guide to all things VoIP
• Wikipedia entry on VoIP - VoIP encyclopaedia
• My VoIP Provider.com - Searchable directory of VOIP providers
• VoIP News - News and information on VoIP