VoIP Solutions for SME

This document is a Voice over IP primer for SME customers who want to understand the benefits of using the technology in their business.

SIP

SIP is the protocol that binds most VoIP systems together. There are other protocols, but SIP offers an open standards solution. This means that services and equipment purchased from different vendors can all work together successfully.

Most VoIP systems will provide SIP account details for you to put into your SIP phones.

Onsite - or Service provider

You can setup a VoIP system by setting up the servers and gateways yourself, connected to your own phonelines and Internet connection.

Or you can use a SIP Service provider or ITSP (Internet Telephony Service Provider) to do it all for you.

Onsite

This is sometimes called IPBX (Internet PBX).

The advantage is that you can keep your existing phone numbers, and that internally the system will operate without your internet connection.

The disadvantage is that you have the upfront cost of servers, software and gateways.

You will need

• SIP Proxy Server - registration, authentication
• SIP Media Server - voice mail, music on hold
• PSTN/ISDN gateways - your link to normal phone lines
• SIP phones

The other possibility is to use something like asterisk which includes the server components (Media, gateway and SIP) all together.

Service providers

If you use a SIP service provider, then you don't have to setup, maintain or pay for your IPBX setup. You can add more features and services to your system by paying more to your service provider, and if you add more extensions you just need to buy more phones.

Although you rely on your internet connection - if it fails then all of your phones go offline

Service providers to try

• coms.com
• Gradwell dot com ltd
• Nplusone
• Voiptalk
• Voipfone
• voip.co.uk
• Voip Unlimited

Please note that these providers are listed without any recommendation. Just so you can see what kind of services people are offering.

What is possible

A distributed phone system, with call transfer, voicemail, ddi numbers, unmetered calls over IP, hunt groups.

In addition, using business class handsets can bring features that are unusual in SME systems, such as caller ID display on the phone and call waiting.