IP address

What is an IP address?

Internet Protocol (IP) addresses are a series of numbers separated by dots. In the same way that street addresses allow us to identify their location, IP addresses allow us to identify internet-connected devices and send data to them, wherever they may be.


nfon.com, also have IP addresses behind them. When you send an email, visit a website, or make a VoIP call, your computer sends data packets to the IP address at the other end of the connection and receives packets at its own IP address. In this way, the internet depends on IP addresses to function.


Why do we need IP addresses?

It’s simple: without them, we wouldn’t be able to identify specific devices or web locations, and we wouldn’t be able to send data to each other. It would be impossible to browse websites, send emails, or make video calls. 
What does an IP address look like?
There are currently two different versions of IP addresses in use: IPv4 and IPv6, and they each look different. 

IPv4 addresses are written as a string of four groups of numbers between 0 and 255, which are separated by dots. A typical IPv4 address looks like this: 

The dots just make these addresses easier for us to read and have no other function.

IPv6 addresses are considerably longer strings of numbers, so they are written using hexadecimals (a numbering system using letters and numbers), which can fit more information into fewer digits. In addition to the 10 digits 0-9, six letters are added a-f. This means that each digit can have 16 different values, which means more combinations. An IPv6 address has 8 groups of four hexadecimals separated by colons rather than dots.

For example:


Often these addresses can be simplified. If you see two colons together it means only 0s are contained between them. So our example could also be written like this:


Why are there two different types of IP addresses?

Basically, because the older format (IPv4) is running out of addresses…

There are over 7 billion people on Earth, but it is estimated that IPv4 only offers about 4.3 billion IP addresses. As the number of end users and end devices continues to increase, IPv4 is reaching its upper limit and will soon be unable to provide new addresses. 

By contrast, the newer format - IPv6 - offers enough IP addresses for everyone. This means IPv4 will eventually be phased out in favour of IPv6. Most devices are already capable of handling IPv6 addresses, so migrating to IPv6 will never be a problem for most users.

Which devices have an IP address?


All internet-connected devices have an IP address, from PCs and laptops, to mobile phones, tablets, routers, switches, and many, many others. IP addresses are usually allocated by routers to every other device on a home network for example. 

For example: 


This router will allocate an IP address to each device that joins the home network: 


If you log on to a network that isn’t your home network - for example the Wi-Fi network in a cafe - your device will be allocated a new IP address by the router in the cafe.

How are IP addresses distributed?

The allocation of IP addresses is managed by the Internet Corporation for Assigned Names and Numbers (ICANN). IP addresses are allocated on a regional basis, and by service provider, and the process is handled automatically by network routers. In the case of VoIP solutions, such as the NFON Cloud Telephone System, IP distribution is also handled automatically.

How are IP addresses used in VoIP?

One of the key technologies needed to place phone calls over the internet is Voice over IP (VoIP). To send data from the right caller to the right recipient, the VoIP solution needs visibility of the IP addresses of the devices involved. This is similar to email and other tools that use IP addresses to figure out where to send information. 

Further information

Voice over Internet Protocol (VoIP)

What is VoIP?

The Voice over Internet Protocol, also called IP telephony, is a method of communication for making calls over a broadband Internet connection as an alternative to regular calls made…

Read more