VoIP - The Basics (Updated 16-06-06)

[mattpark]

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. 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.

How it works?

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).



Why use VoIP?

1: Cut your telephony costs. Most calls to other VoIP phones are free, and calls to other lines are competitively priced.

2: 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!

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.

What you need

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.

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: This gives you a VoIP external number: which is what other people dial to call you.[/img]