Voice over IP (VOIP) in business

VOIP (or, making phone calls over the internet)
Joe Aliferis is a Director of Newforms.co.uk Ltd. A web technology development consultancy based in Brighton.

What is VOIP?
Voice over Internet Protocol. The technology used to transmit voice over a data network using the Internet Protocol. This allows you to make telephone calls using a broadband Internet connection (digital) instead of a normal (analog) phone line and, in some cases, these calls can be free.


How do I get VOIP services?
There is more than one provider of VOIP services. Some may only allow you to call other people using the same service, but other providers may allow you to call anyone who has a telephone number - including local, long distance, mobile, and international numbers.

Also, while some services only work on your computer or a special VOIP phone, other services allow you to use a traditional phone through an adaptor.

This diagram illustrates the various configurations of equipment needed to make VOIP calls

What Setup do I need?

Computer method

1. A fairly modern PC (or Mac)
2. VOIP software
3. A headset or handset
4. An internet connection (preferably broadband)

Adapter method

1. A telephone
2. A VOIP adapter
3. An internet connection (preferably broadband)




VOIP providers

Vonage
http://www.vonage.co.uk

This is an example of a provider that makes use of a telephone adapter, so no computer or software is required (the little box does it all). However, like all these providers, broadband is required. It’s essentially a pay-as-you-go service.

Sipgate
http://www.sipgate.co.uk

Another example of a pay-as-you-go VOIP provider. In common with this type of provider, calls to other IP networks are free and a published table of tariffs is available so you can compare the cost of calls to landlines, mobiles, international numbers etc.

Skype
www.skype.com
Skype is different from the two previous providers in that it requires a computer with a headset (or a Skype handset) to use it. However, Skype is fast becoming ubiquitous and Skype call rates are the cheapest by far. Skype will allow you to make free calls to anyone with a Skype account, anywhere in the world and a basic Skype account is free to setup.

Skype also offer fee-based services like ‘skype out’ that allows you make calls to ordinary landlines anywhere in the world for very low rates and ‘skype-in’ that allows you to have a phone number and voicemail so others with traditional phones can call you on your skype setup.

See www.skype.com/products/skypeout/rates/ for more information

Some points about Skype

The Skype client is easily installed and, other than choosing a username, no configuration is required.

Skype clients also work behind firewalls and Network Address Translation (NAT) systems. In other words, over your local network as well as with a direct connection.

Skype is not a telephony replacement service and cannot be used for emergency dialling.

You can use your computer whilst on the phone

You cannot make phone calls while your internet connection is down

VOIP will work over a wireless connection

Almost as soon as you log on your Skype contacts know you are there

Calls are encrypted using latest AES encryption



VOIP and bandwidth

When deciding whether to use VOIP, an important issue to consider is how much bandwidth you have through your internet connection.

Most ADSL broadband lines only have 256k upload, regardless of the download speed. Cable broadband can be even slower. Each VOIP phone call takes approx 40Kb of bandwidth so it’s recommended you only use a maximum of 5 VOIP phones per broadband connection. Of course, you could have 10 phones in total and count on the fact that not all will be used simultaneously. Bear in mind that many simultaneous VOIP calls may affect your overall network performance.

Joe Aliferis is a Director of Newforms.co.uk Ltd. A web technology development consultancy based in Brighton.