VoIP phone system installation

Done away with your old office phones, but wondering how to install a VoIP phone system? Read on for the 6 key components essential to installing your VoIP

This page will cover the process of VoIP (Voice over Internet Protocol) phone system installation.

The setup covered will detail the installation of SIP (Session Initiation Protocol) phones, used for private IP (internet Protocol) calls. This means that the installation will have no connection to a previous analogue setup.

Note: Before you get started, make sure you’ve read our our pages on what is VoIP? VoIP phone costs, and the best VoIP providers and phones.

Also, while this guide is a brief how-to on VoIP phone installation,professional assistance is strongly advised for complicated or potentially dangerous electrical installations, professional assistance is strongly advised.


Use the following links to jump to the most relevant section for you:

  1. VoIP phone system installation: what you’ll need
  2. VoIP phone system installation: the first steps
  3. How to install a hardware VoIP phone system
  4. How to install a software VoIP phone system
What’s the difference between hardware and software VoIP phones?

  • Hardware (IP phone) – hardware IP phones that look like regular office phones, but use VoIP technology; often called IP phones
  • Software (softphone) – software installed on a computer/mobile device, enabling it to be used as a VoIP phone; often referred to as a softphone

VoIP phone system installation: what you’ll need

Here’s a list of the six essential components you’ll need to install a VoIP phone system:

  1. A strong broadband internet connection
    The higher your call volume, the higher the bandwidth required. For more detail on how many phones your internet connection (measured in Mbps: megabytes per second) can support, please see the helpful table below.
  2. Wired Ethernet router
    While your budget will have an impact on this decision, you will need a highly capable VPN (Virtual Private Network) router with a high quality of service and strong concurrent connection volume. If you’ll want to use your VoIP system remotely, then the VPN function will be essential.
  3. A computer functioning as the PBX (Private Branch Exchange) server
    A VoIP phone system requires very little from the PBX, unless you have a lot of phone users.
    Wondering what PBX means? Then be sure to check out our article on what is PBX?
  4. IP Phones (hardware)
    You’ve got a lot of choice here – from full-colour touchscreen systems to cordless Wifi phones, it’s possible to choose the hardware that best suits your business needs. To fully assess what’s available on the market, take a look at our page on the best VoIP providers and phones out there today.Note: it’s important to check that your hardware of choice is also compatible with your PBX server.
  5. PBX (Private Branch Exchange) server software
    PBX software is installed on your server to act as the nucleus of your local phone network. This software facilitates all of your phone system’s functionalities, ensuring the smooth running of your business calls.
  6. A VoIP provider
    Your business needs to subscribe to this service. This is similar to having a mobile phone contract, as it is separate to the phone itself, but essential to your ability to make external calls. Without a VoIP provider, you’ll only be able to dial other extensions within your office.
Bandwidth (upload speed): Maximum number of lines supported by this bandwidth: Recommended number of lines on this bandwidth speed:
500 Kbps 5 0
1 Mbps 10 2
5 Mbps 50 11
10 Mbps 100 22
30 Mbps 500 67

How to install a hardware VoIP phone system

You’ve seen the components list – now for the method. Assuming you have all of the essential elements, the following steps detail what you need to do to install a hardware VoIP phone system.

Sometimes it’s easier to visualise a system. This diagram is roughly what a network layout for a hardware VoIP system will look like:

VoIP phone system layout

Hardware VoIP phones, also known as IP phones, are very similar to conventional office phones. While IP phones both look and function in a similar way to analogue phones, the difference is that they read digital, rather than analogue signals.

As the above graphic shows, the PBX server merely sits within your network, like any other device. Providing it’s on the same network, your hardware (IP phones) can then use the IP address to connect to the PBX system.

Your PBX system must be connected to your network via a standard NIC (Network Interface Card), and must be assigned a static IP address. This makes your PBX consistently accessible.

Your VoIP network can then be installed on the same subnetwork for ease of configuration. It is also possible to install the entire VoIP network under a separate subnetwork altogether, but this is a more complex approach, configuratively speaking.

Connecting the phones:
Now we’ve taken a look at the tech-heavy bits, it’s time for the easy part – plugging in your hardware. For this, we’re going to assume that your phones are IP phones, as this is the hardware that is compatible with the system and the most office-friendly.To connect your IP phones, simply connect them to the same network as the PBX via an Ethernet cable (for some IP phones, a power-over-Ethernet adapter is also necessary).

Once the phone is up and running, it will locate and conjoin with the PBX system

What about the router?
For complete VoIP compatibility, your router will probably require a few configurative tweaks. Possible changes include:

  • Enable UPnP (Universal Plug and Play)
    This is a set of networking ‘protocols’ that allow networked devices to discover one another. In other words, UPnP will allow your VoIP phones to locate and conjoin with the PBX system.
  • Enable NAT (Network Address Translation)
    This is related to your IP address. NAT modifies your network address information to remap one IP address into another during transit over a traffic routing device.
  • Open Firewall port UDP:4569 to your PBX static IP address
    Firewall port UDP:4569 works well in network address translated environments. It’s a TCP port – meaning that it uses Transmission Control Protocol – and enables two hosts to establish a connection and exchange data, guaranteeing communication and the delivery of information between devices.
  • Forward ports 5060 and 4569 to your static IP address
  • Forward ports 10001 – 20000 and port 4569 to your static IP address

Basically, to connect your VoIP hardware, you simply need to plug it in via an Ethernet cable and make sure that the router is configured for maximum compatibility.


How to install a software VoIP phone system

The following steps detail how to set up a software VoIP phone system. A software system differs from a hardware system insofar that the software simply needs to be installed on a computer or mobile phone, enabling it to be used as a VoIP phone (and thus making it a softphone).

Headsets and handsets can also be plugged into a computer for ease of use when it comes to making and receiving calls, but the basic principle of a software VoIP solution is that it is a programme to be installed, rather than a piece of kit to be plugged in.

Steps to software VoIP phone installation:

    1. Log in to your PBX server
      You do this by entering your chosen IP address into your server’s domain.
    2. Set up your VoIP provider
      This means configuring your server to communicate with lines outside of your office via your chosen VoIP provider. Without this step, your network will only be able to communicate internally.
    3. Set up the TRUNK (on your PBX server)
      This is the basis of communication between your network and your VoIP provider. To do this, you need to enter details that should be provided by your VoIP provider.

Setting up the TRUNK (the information you’ll need):
TRUNK name: name of provider
Outbound CallerID: the new VoIP number you were assigned
CID Options: set to ‘allow any CID’ during setup, then change to ‘block foreign CIDs’ once setup is complete (this keeps your network secure)
PEER details: input information about your provider (this information should be provided by your provider)
Register string: information that authenticates your network with your provider via account ID and password

    1. Set up an inbound route
      This will allow you to receive external calls. There’s a pretty much unlimited amount of inbound routes you can set up on most systems, but each that you want your network to handle has to be represented by a different number.
    2. Set a destination for the inbound route
      This determines where calls to your inbound route will be directed to. For example, you may wish to set this directly to your receptionist’s extension. Alternatively, you may wish to set up a digital receptionist who will greet incoming calls with a welcome and instructional message.
    3. Configure your extensionsThis is a two-part process:
      Part A = configuring the PBX extensions
      Part B = configuring the device that’s hosting the VoIP software itself

      Every phone or computer (the software ‘host’) will be different, and therefore the setup process here will be too variable to explain in detail. However, it should be a fairly straightforward process that your chosen hosting device (or devices) will be geared up to walk you through logically.

      Your phone or computer will probably have a web admin feature that’s reachable by entering the device’s IP address into a browser. Then, you’ll have to specify the extension and password you set up with the IP address of your PBX server.

7. Setting up outbound routes
Having completed step six, you should be able to receive external calls. To make calls, you need to configure your device to be able to handle different dialling scenarios.

There are two basic scenarios you need to set your device up for.

Scenario A: dialling an internal extension

On your chosen software’s interface, you should be presented with the option to ‘add route’. Select this, and then complete the steps presented to you. These steps will most likely ask you to input the following data:
Route name: Internal
Route type: Intra-company
Time group: Permanent
Dial pattern: Enter in the ‘match pattern field’: ZZZZ

Then save this route. This will tell the system that when someone is dialing a four digit number, it should be directed to an internal extension. Putting in more or fewer Zs will vary the number of digits in your internal extensions.

Scenario B: dialing an outside phone number

Again, you need to select the ‘add route’ option on your software’s interface. For this scenario, you will likely be asked to input the following information:

Route name: Outbound
Route type: Non-checked
Time group: Permanent
Dial patterns: Add as many or as few patterns here as you like. This will allow the VoIP system to make external calls to normal, external numbers.
Trunk sequence: Input your VoIP trunk sequence here

Then, ‘submit’ to save the route.


What’s next?

All being well, you should now be able to make and receive calls via your VoIP phone system. Whether you have a hardware or software VoIP system, it should have been relatively quick and easy to get set up.

For more information on phone systems, take a look at our dedicated channel of advice and ‘how to’ pages. Or, to compare suppliers, simply fill in the form at the top of this page.