As well as linking to conventional phones and phone lines, system using voice over IP (VoIP) allow phone communications to be run over computer networks (ethernet) and the Internet. You can have a phone number in a different city, country or continent that when dialed calls you office phone system (PBX). Voip service providers can also route international calls over the internet so that if you have an account with one of them you can make international calls at any time of day from your desk and pay a lot less for your call than over a normal land line.
- VoIP Systems - some basic terms
- softPBX What is a softPBX and what does it do?
- trixbox® Where does it fit in?
The flexibility of communicating using VoIP gives rise to many possible arrangements and here are a number of configurations to show how you can grow from one phone, to many phones to phones at multiple sites.
The Links at the top of these pages allow you to navigate the following solutions
- Basic Home Office Installation with one IP Phone
- Basic Office Installation
- Adding existing PSTN lines
- Adding more phone extensions in the office
- Adding remote extensions
- Linking PBX’s to form a multi site system
We have also put together a page with a more technical introduction to VoIP and links to a number of resources for VoIP.
VoIP Systems
VoIP systems are based on number of interconnected elements including:
- IP Phone
- Network Phone, either hardware or software based.
- softPBX
- A software based PBX (private branch exchange) that provides the phone system functionality.
- Firewall
- Device to protect your private network from external attack. May be part of your router or cable termination.
- Router
- Device connecting your home or office network to the internet.
- ITSP / VSP
- Internet Telephony (or VoIP) Service Provider giving users access to incoming or outgoing telephone services. The service may be for one line or multiple lines, then regarded as a Trunk.
- DDI / DID
- Direct Inward Dialing Number.
- Internet Cloud
- The global space of the internet or world wide web.
- Network Switch
- Interconnects the network components e.g. IP Phones; softPBX; Firewall; etc.
- FXO
- Foreign Exchange Office. This is the interface that receives the incoming call. An FXO port on a PBX will answer an incoming call. On a softPBX you would normally have a PCI card that has 1 or more FXO ports each connected to an incoming POTS line.
- FXS
- Foreign Exchange Subscriber. This interface generates the dial tone to indicate a call, normally this will be connected to an analog telephone. On a softPBX you can install a PCI card with 1 or more FXS interfaces and these will connect to (conventional) analog phones.
softPBX
To achieve the best service from the phones and have the range of functions normally associated with an office phone system you need a PBX. Part of the !Voip revolution has been driven by the availability of PBX’s that are software based and run on a PC or server. One of the most widely used softPBX’s is based on Asterisk software. Our services are based on systems running Asterisk in some form, eg trixbox® or AstLinux
To make a successful softPBX a range of configuration tools and packages have been added to make a fully functional softPBX. We have softPBX’s running trixbox® and AstLinux.
The key features of a softPBX are provided by the administration interface operated through a web browser. With this, the structure, configuration, operation and maintenance can all be remotely managed from any PC on the network. Whilst this requires experience it does make for a very powerful and flexible PBX. The trixbox® interface uses the very powerful freePBX application.
trixbox® Where does it fit in?
trixbox® is a complete software based PBX and it allows a PC or server to be turned into a superior PBX. PLEASE NOTE when installing trixbox, all existing files on the PC are DESTROYED, the hard drive is formatted and a completely new operation system (Centos Linux)is installed. Apart from the operating system, trixbox installs a comprehensive range of tools to build and configure the PBX.
Once installed most of the configuration and management can be carried out using freePBX in a web browser on another PC on the same network. Whether you use a PC or server depends on the amount of traffic your system will handle, the number of concurrent calls required, and to a lesser extend the numbers of phones and phone trunk lines connected. You can also add telephony cards that allow conventional, ISDN, E1 and T1 lines to be connected to your PBX. These factors will also affect the specification of the PC or server that you use.
Telephone handsets using Voip will be connected via ethernet to the local network or remotely over the internet. Analog telephones can be successfully used but need cabling back to the server where they will be connected to the PBX via an interface card with FXS ports.
Once installed and configured, and depending on the hardware chosen, you have a PBX that can be used in a small home office, busy city office or a call centre, all based on trixbox. Our trixbox® page has more details on the facilities offered by a trixbox based PBX.
trixbox® is a registered trademark of Fonality, Inc.
