Everything you wanted to know about VoIP explained! We cover the basics here in enough detail to get you started, but there is plenty of help if you get stuck.

If you want to know all of the ropes first, then our VoIP Tutorials will give you the full coverage of this exciting technology. In addition, our VoIP FAQs tackle some of the most frequent practical issues. In the unlikely case that you don't find what you need there you can always contact us for further clarification.

You can download the entire manual as a printable Adobe Acrobat (PDF) document (572Kb).

VoIP: the basics

What is it?

VoIP (Voice over Internet Protocol) is a way to make phone calls using the internet as the transmission method, rather than a landline. With UK-247's system, you can make and receive calls from other VoIP users, mobile users, and people with ordinary landlines. The integration between any ordinary line and VoIP is complete, and undetectable to callers.

Just like a modem converts digital signals from the PC into analogue (voice) traffic for transmission over a phone line, a VoIP-enabled phone or VoIP adaptor converts your voice into digital packets (using the special SIP protocol) for transmission over the internet. If you make a call to another VoIP phone, the opposite process occurs at the other end, and your voice emerges intact from the ether. If you make a call to a mobile or landline, gradwell dot com's gateway decodes the call and sends it on as an ordinary voice call to the telephone exchange (PSTN).

See the diagram: user A dials the number for user B. The VoIP adaptor logs onto the Gradwell routing server, which looks up the destination and sets up the call. Thereafter, the voice traffic passes directly over the internet between A and B.

See the diagram: When A calls C, who has a conventional landline or mobile, the VoIP adaptor logs on as before. The routing server looks up the destination and finds it is a PSTN (standard) number. The call is routed via the Gradwell PSTN gateway into the PSTN network as a normal call. Thereafter, traffic passes directly via the gateway.

1: Cut your business telephony costs. All calls you make to other VoIP phones are free, and calls to other lines are competitively priced.

2: Get a fully-featured PBX system for your business for a very modest rental cost. With every VoIP number, you get ten extensions on your virtual PBX, with all the facilities you would expect: voice menu, extensions for specific people, hunt groups, call forwarding, etc. All this is simply set up from an online control panel, which also gives you access to detailed call statistics and billing information.

3: You can configure your system to give whatever impression you want to customers. For example, if you have associates or employees in other areas of the UK or even abroad, you can give them all extensions on the same number, or their own numbers with the same area code as your head office. No-one need know whether you have city centre offices, or a virtual office!

Small to medium-sized businesses with several employees, and especially those with distributed offices and teleworkers, are likely to get the maximum benefit from our system, which has been carefully designed to provide all the features that you will need in a professional package.

You can assign one or more external numbers that people can dial; these can be mapped to a voice menu so they can chose an internal extension, or directly to an internal extension, hunt group, or diversion to another number. Calls that go unanswered can either be forwarded to another number, or a voicemail.

There are three main elements to the service:

1. A VoIP-enabled telephone. This can be an all-in-one handset, or a normal handset plugged into an adaptor, or a softphone: a computer program that uses a microphone and headphones attached to your computer to emulate a real handset.
   Our preferred solution is the Sipura SPA 2002 adaptor, which allows you to connect one or two handsets, and has the advantage that you can connect other analogue devices like fax machines. It also has a number of useful inbuilt functions, including call waiting, caller ID, and call back if busy.
2. An internet connection. A leased line or ADSL/cable broadband is ideal; dial-up (ISDN or ordinary telephone line) or a satellite internet connection will likely cause a reduction in sound quality. A standard 256Kb ADSL connection can accommodate 2-3 simultaneous calls; if you expect to need more frequently, you may wish to upgrade to a higher-bandwidth package.
3. An account with a VoIP service provider: gradwell dot com in this case. This gives you a VoIP external number: which is what other people dial to call you.

In general there is a £4.99 charge for setting up geographical area codes (01, 02) and a £7 monthly rental. With each number, you get one inbound and one outbound line, and ten internal extensions.

The Virtual Centrex service (which gives you the facility to make VoIP calls on your number and provides your virtual PBX) is included in the cost of the line rental.

Calls that you make are charged as follows:

• VoIP to VoIP calls are always free.
• VoIP to PSTN calls other than 0800 numbers are charged per minute, according to the tariff sheet - for example, 1.25p/minute for calls to geographic numbers in the UK, and 12p/minute to mobiles. Please see the web site for full terms and conditions.
• Calls that you forward or divert are charged according to where the redirect goes.