Voice over Internet Protocol: The Art of Switching from PSTN to IP

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 over an analogue phone using the PSTN. These VoIP calls can happen entirely over the Internet but where required, gateways also link to the PSTN. This means that VoIP users can still connect to anyone with a telephone number including local, mobile, and international numbers. VoIP services can be accessed from a computer with a so-called softphone, from an IP phone, from a smartphone or from a conventional landline phone that is connected to a VoIP adapter.

What is the PSTN?

PSTN stands for Public Switched Telephone Network and is generally known as the traditional phone network. It has been connecting people since the late 19th century, at first over copper telephone lines and later using fibre optic cables, satellites, and undersea cables. All of these are interconnected by switching centres which establish a dedicated connection – or circuit – between callers.

Voice signals can then travel over this circuit. When the caller speaks into his handset, the caller’s phone translates the sound waves into electrical signals. These are transmitted over the PSTN (converted to optical signals for part of the way, so they can travel via fibre optic cables), and the phone at the other end of the line then translates the received signals back into sound.

The arrival of Voice over IP (VoIP) technology – essentially, transmitting voice calls over the Internet rather than the PSTN – challenged traditional telephony and fundamentally changed how people communicate.

How does VoIP work?

In order to make and process VoIP phone calls, and to benefit from additional features that are possible with IP telephony such as conferencing, call recording or Computer Telephony Integration (CTI), businesses need a dedicated VoIP solution.

Switching data packets over VoIP

The VoIP technology’s key function is to convert the caller’s voice into a digital signal that can then be transmitted over the Internet.

  1. Audio is digitised
    As the caller speaks into the microphone or handset, the sound waves are digitised and then broken up into pieces called “packets”, each with a unique label.
  2.  Data is transmitted securely over the Internet
    These data packets can travel securely over the Internet to reach the recipient.
  3.  Data is decoded and reassembled
    At their destination, they are reconstructed and converted back to sound.

This packet switching is more efficient than the traditional circuit switching because it doesn’t rely on a fixed physical path between source and destination, which means several separate calls can securely share the available bandwidth.

How does VoIP work?

Top VoIP benefits for businesses

  1. Free internal calls
    With a cloud telephony solution, you can call anyone in your organisation completely free of charge, including colleagues in different offices and branches in different countries. There’s no need for expensive equipment or service provider contracts.
  2. Cheaper external calls
    Typically, VoIP telephony is considerably more cost-efficient than traditional landline and mobile telephony. This is because VoIP transports voice data over the Internet. This is a contrast to traditional calls over the PSTN network, which require a dedicated connection for the entire call duration. Compared to conventional phone systems, a VoIP platform can therefore reduce the cost of calling external mobile phones as well as landlines.
  3. Less hardware
    Given that the best VoIP solutions are hosted in the cloud, they provide the full range of business telephony features without having to install costly physical telecommunications infrastructures. This saves costs while also simplifying and speeding up deployment.
  4.  Easy mobile working
    With a dedicated VoIP app – such as the Cloudya app from NFON – employees can also access all telephony features of the cloud telephone system on their mobile device. Each user has a single number for landline and mobile, which makes it easier for colleagues and customers to reach them.
  5. Pre-integration with Unified Communications tools

Integrations add even more functionality for more efficient business processes. As an example, NFON’s cloud telephony system integrates with Unified Communications tools such as Microsoft Teams. This integration enables users to make phone calls within the familiar Teams environment where they also access other UC functions, and to benefit from lower costs.

Can you use VoIP to call non-VoIP users?

Yes, in the majority of cases, VoIP users can call non-VoIP mobile phones or landlines, which means you can get all the simplicity, flexibility and cost savings of VoIP, whoever you’re calling. VoIP solutions use something called a VoIP gateway to connect with regular mobile phones and landlines via the PSTN network. The VoIP gateway also converts calls from traditional phones into IP, so anyone in the world can call you on your VoIP phone.

How secure is VoIP?

Reliable VoIP solutions are hosted in highly secure data centres and use proven technologies such as encryption to protect your voice data. NFON’s VoIP solution for example is hosted in geo-redundant data centres. The fact that our solution is highly secure and highly available has helped us achieve compliance with EU Electronic Communications legislation. The data centres where our solution is hosted are also fully compliant with ISO/IEC 27001 Information Security Management standards, gaining the trust of our clients and providing them with complete peace of mind.

Which devices do you need in order to migrate to VoIP?

One of the main advantages of VoIP is that is offers multiple device integration. This allows users, for instance, to also have their office extension on their mobile phone, giving them complete freedom of communication, no matter whether they are working remotely or in the office.

There are four main ways in which your current phone system can be migrated to VoIP.

  1. Make and receive VoIP calls over a PC or laptop
    A laptop or a PC can easily be converted into a VoIP enabled device and the user can adapt the PC or laptop to his needs using their chosen headset. With instant messaging, emails and video calling also taking place on the computer this means the user can access all communication channels in one place. As an example, NFON’s Cloudya lets you make calls directly from your PC or laptop, without the need for a separate desk phone.
  2. Use a VoIP phone
    VoIP phones such as IP and SIP (Session Initiation Protocol) telephones typically have Ethernet connections and can be plugged directly into a modem or router. SIP phones can also handle multimedia communication such as video calls.
  3. Use your existing phone to make VoIP calls
    An Analogue Telephone Adapter (ATA) allows the user to plug the phone into a modem or router, thus converting analog phone calls into IP packets. Converting existing phones into IP phones can help you maximise returns on investments in existing office equipment. 
  4. Use your mobile device to make VoIP calls
    Installing a dedicated app allows your smartphone to connect to your Internet telephony system. You can then be reached via a single phone number, irrespective of where you are – which makes business communication and collaboration much easier. The best Internet telephony solutions also help reduce costs by always choosing the most efficient mobile connectivity option - whether that is WLAN or mobile data on a carrier network.

    Above and beyond making calls, NFON’s Cloudya App , as an example, also lets users access all the advanced PBX features of their NFON telephony system – voicemail, blacklisting and whitelisting, call forwarding and more – from their smartphones. They can use the “meet & share” function for easy collaboration, with excellent audio and video quality. Additionally, using the app means businesses can consolidate two costly lines (and service providers) and move to a single service provider. This saves costs and simplifies supplier management.
softphone, voip, mobile, laptop

How can I deploy VoIP in my business?

The main requirement for deploying VoIP is a good Internet connection. With NFON, everything else is hosted in the cloud on our secure servers, so you can access your new telephony platform quickly and easily, with no need for complex software installation or hardware deployment.

NFON has prepared a variety of resources to help you find out more about Internet telephony and the capabilities of our cloud telephony system.

 

Further information

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