Creating a VoIP Phone System

A Voice over Internet Protocol (VoIP) system is considered a complex communication infrastructure, even from a high-level perspective. However, the truth is somewhat different – even though VoIP is, in fact, technical in its details, it has been abstracted by several projects in order to make it simpler to use, thus making it pretty easy to set up.

Before we dive into the actual steps of creating a VoIP phone system, let’s go over some basics. VoIP merely means “Voice over IP”, which is a generic term for transmitting real-time voice sessions via the internet. However, it fails to take into account ‘how’ this is done. There are a few components involved when you are talking about a VoIP system, which include SIP Endpoints and SIP gateways. To summarize, there are SIP Endpoints, which are basically the client examples of your customers. These could either be an open-source and cross-platform communications client, or software installed on your customer’s computers (popular software include Bria and Jitsi). Other possibilities are SIP phones, such as Polycom Phones or SNOM Phones.

In addition to the customer-facing endpoints, there are SIP gateways that actually translate VoIP into mobile and conventional fixed-net networks. They act similar to customer-facing clients, but often are able to manage multiple calls at once. Moreover, they are typically connected through multiple ISDN E1 or T1 lines, and at times an SS7 control layer is also used on top.

For you to be able to launch a communication session, you need a signaling protocol that tells all the involved parties that wish to communicate with whom, and which media capacities may be used (for instance, fax, voice, audio/video, etc.) There are various protocols out there – the popular one of which is SIP, the Session Initiation Protocol.

A key part of VoIP phone system creation is the registration of customer endpoints. This means if a customer begins its SIP client, the client indicates the SIP server at which port and IP it is approachable in case there is a call directed towards the customer.

Another important step that you will need to take care of is SIP VoIP configuration. If you can, it is better to set up your system with a temporary or new number, prior to putting your present ones over. Ensure your internal phones work properly, and can make and receive calls – especially if you are substituting analog handsets with VoIP phones. You should also pay some attention to your “dialing plan”, the rules by which the phone system determines where to direct calls. In this era of mobiles, the majority of people are so used to pre-dialing, where you punch in a number and then simply press dial, or pick up the handset. Getting this part right can make a lot of difference.

Creating a VoIP Phone System with Asterisk

If you have spent any time doing research regarding VoIP business phone systems, then you have most likely come across the name “Asterisk”. It is not only one of the most popular names in telecommunication, but also the system running behind the scenes of numerous other big names in telecom.

Asterisk is free and open-source software, which runs PBX systems and can also be automated into a Do-it-Yourself business phone network. It can be configured with all the features that you would expect from an enterprise-class PBX, and at the same time incur very few of the enterprise-class hardware costs. To create a VoIP phone system with the help of Asterisk, here’s what you will need:

  1. A strong broadband internet connection – more call volume requires a better and faster bandwidth connection. Asterisk has no special requirements for LAN – you just need to have one in place.
  2. Wired Ethernet router – you have numerous options here, but your budget will probably be a good determinant of this. A decent router that has QoS and a good quantity of concurrent connection volume should get the job done nicely. The VPN function will also come in handy if you wish to use your VoIP phone system from a home office or remote home office.
  3. A computer that will act as the PBX Server – the requirements for this system are quite low unless you have too many phone users.
  4. IP Phones – there is a wide variety of IP phones available in the market from touch-screen and full-color ones to Wi-Fi cordless ones. Make sure that whatever phone you choose, it is compatible with the PBX server of your choice.
  5. PBX Server Software – this software is what will connect to your server and act as the main source of your local phone system. It will allow you to do everything you can imagine with your phone system.
  6. VoIP Provider – this is a service that you will need to subscribe to, similar to how you would with a regular phone company, which in turn will you to actually receive and make from outside of your office. Without a VoIP service, you will only be allowed to dial other extensions in your office.
Installing Asterisk

Without a doubt, installing Asterisk is a complicated procedure, and although there are various online tutorials that can be very helpful. In other words, the installation process may seem pretty straightforward, but it can take quite a bit of your time. If you have ever installed a brand new operating system on your PC, then you are familiar with the basic process that entails the Asterisk installation. After burning the installation disc, you put it into the disc drive. Next, you feed the computer’s BIOS settings (the fundamental hardware settings) and set the PC to boot from the DVD/CD drive rather than from the hard drive (which is normally selected automatically). Upon reboot, your computer will load from the installation, and the installation process will start.

Additional Resources