Beginners Guide to...VoIP

Monday 31st October, 2005
You may have heard the word VoIP thrown around a lot in recent years, this document is intended as a guide for people who wonder what it is, how it works and how it may be of use to them.

What is VoIP?

VoIP stands for Voice over IP. IP stands for Internet Protocol and is the means used to get data traffic across the internet. So if you read a web page or download a file, it's IP that transports this to the screen you're looking at. In case you hadn't already guessed, VoIP allows voice communication to be transferred over the internet, most importantly phone calls.

What's the Advantage of VoIP?

Traditionally phone calls have been carried over copper wires and fibres. When you dial a number, the telephone exchanges en-route connect your phone to the end by a series of electronic switches. Basically when a call is connected, there is effectively one piece of wire between you and the other end. The longer it is, the longer the wire. This usually results in increased costs.

With the breakthrough of the internet, the majority of homes and business now have a fixed cost data connection to their premises. No matter how much they download or surf, the price is the same. VoIP exploits this fixed cost by enable phone calls across the fixed cost, unmetered connection. Even long distance or international connections can be made at little or even zero additional cost.

How does it work?

Just to confuse people, there are many kinds of VoIP. Using voice chat in MSN or Yahoo messenger could be regarded as VoIP, so could the highly publicised Skype; but these are all proprietary systems. To talk to someone using MSN, the person at the other end also needs MSN. The same applies to Yahoo and, to a great extent, to Skype. They use their own special system that isn't open and won't connect to other systems easily.

True VoIP should really be based on the SIP system which is the recognised standard. Any SIP compatible device can talk to any other, you don't even use a PC. Any SIP telephone can call another right over the internet, you don't need any additional equipment or even a phone provider. Just plug your SIP phone into the internet connection, configure it and then dial the other person right over the internet.

In all VoIP systems, your voice is converted into packets of data, like little files, and then transmitted to the recipient over the internet and decoded back into your voice at the other end. To make it quicker, these packets are compressed before transmission, a bit like zipping a file.

Service Providers

SIP can be a little confusing for end users, so there are a number of VoIP resellers out there who will help configure your equipment and call other SIP users via their network free of charge. You configure your SIP phone to connect to your VoIP provider and just dial a number as you did before. Being internet phones however, the numbers will be different.

On top of a free internet phone service, VoIP service providers also allow you to call standard telephones anywhere in the world. There is a fee for this but, as internet telephony is much lower cost, the charges are much much less. Transatlantic calls for example can be made for 1-2pence a minute. Many providers supply unlimited local calls and other services just as standard telephone server providers do too.

Value Add

On top of what you expect from a normal telephone provider, VoIP resellers often bundle many services free of charge. Things like caller-ID, 3-way calling, multiple phone lines, voicemail, divert etc. can often be had for little or no cost.

But what if I like my existing phone handset?

If you already have a nice telephone setup in your home that you like, you can simply buy a VoIP adapter. Some providers include this as part of their service. This allows a standard normal (analogue) telephone to be connected directly to the internet and you can use all your phone memories as you did before.

So what's the catch?

Obviously nothing is ever as simple as it sounds. New technologies aren't perfect and pricing often reflects this, if it wasn't cheaper nobody would switch.

The main problem with VoIP applications is bandwidth contention. This complicated term isn't as difficult as it sounds. You might have anything from a 512Kb broadband connection to 8Mb and beyond, dial-up isn't suitable for VoIP. It doesn't matter how big this connection is, it can still get busy.

Imagine your internet connection to be a water pipe. The wider the pipe, the bigger your connection. So there you are in the shower and somebody flushes the toilet. In the shower you gets scalded or frozen as the water pressure changes. In the internet world, your connection drops and your phone call with it. This can easily lead to a high number of disconnected phone calls if it's not carefully managed. The problem is not usually with the speed of your downloads, it's the upload that has the bottleneck.

Whilst you may have a massive 8MB connection downstream, you may find that your uploads are still limited to 256Kb...not a lot. A VoIP phone call requires at least 100Kb or dedicated bandwidth and without this, you may find your phone calls less than satisfactory. To resolve this problem, there are now ranges of internet routers to use with your existing cable or DSL connection. These are VoIP aware and will dedicate the bandwidth to your phone call when you need it but free up all the bandwidth for other use when you're not on the phone. Some VoIP service providers will supply a compatible router with your connection package, it's essential.

Can I keep my existing phone number?

At the time of writing this document, I don't believe any UK VoIP providers can transfer your existing number to their service. This is planned in the future however. Of course, not all VoIP systems will give you a phone number. Some, like Skype or MSN, don't allow incoming calls from standard phones so you'll still need a normal phoneline for this, defeating most of the objective of switching to VoIP.

What if I move house?

Your phone is connect to your internet connection, not your phoneline. If you move house, just take your phone or adapter with you and your phone will be online wherever you plug it in. Some VoIP users even take their adapter travelling with them, using their own phone in hotels and friend's houses.

Which providers do you recommend?

VoIP is a very new technology and the experience of both providers and their staff in the industry is increasing all the time. I had a very poor experience with Gossiptel and swiftly moved to Sipgate who have provided a very good service although they don't offer many features like call divert. Whilst they're limited feature wise, their service is completely free. Alternatives such as Vonage offer a feature rich service, but there is a base fee of around £10/mth. Service levels between providers varies a lot, it can also depend on who you talk to at each firm. The same can be said with existing providers though, ever had a problem with NTL or BT???

How much are you saving?

Before switching to VoIP my phone line rental was a minimum of £9.99 with a charge on top for caller-ID and phone calls. Now I have a free phone line and free caller ID. Also, every call I make is cheaper than before. I've yet to actually spend £9.99 in a single month since the switch.

What else do I need to know?

To use VoIP you need a broadband connection. This can be from cable, ADSL or another similar connection. VoIP is ideal for cable users but ADSL users may find that they have to have a BT phone line in order to have ADSL anyway. This means you're obliged to pay the £9.99 fee whether you use the line or not! This is swiftly changing as BT are slowly being forced to let go of their monopoly of the "local-loop" phone system. The savings will be much much greater if you can get a broadband connection that doesn't include a standard phone line.

The future

It's predicted that all phonelines in the future will be VoIP based, it's simply not cost effective for each property to have 2 different connections when one can be used for both. BT have even started installing VoIP based phone lines onto new residential developments instead of standard analogue phones.

Where can I go with further questions/comments?

Post a comment below or email me via the contact page.

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