You dial a number, or click a contact, and somehow you’re talking to an intended correspondent in another location… Perhaps in another country. When you think about it, it’s pretty miraculous, but thanks to the PSTN network this capability has been with us in one way or another for decades, so we don’t question it. We only notice it if it doesn't work for any reason, and we probably don’t pay a lot of attention to just how our voices miraculously travel from one location to another and back again.
How did we get to Voice over Internet Protocol?
The V in VoIP stands for voice, and let’s face it, human communication and connection has always been about transmitting voice signals from one place to another.
Sending messages through history
There are lots of ways of transmitting voices, depending on the distances involved. For example, if you’re pretty close by each other, you can talk — or if it’s a little bit further, shout! The sound moves through the medium of air, with each molecule joggling the adjacent ones and transmitting your message. As this spreads out in all directions, it degrades pretty quickly and won’t go far, though you can improve it by using a megaphone or cupping your hand around your mouth.
Over the centuries humans have tried many ways of sending messages and signals further afield, by attaching meaning to things which can be seen or heard over longer distances- Perhaps that message could be chunked and relayed in stages — like networks of fire heights along coastal routes to warn of enemy invasion: one watchtower would spot ships on the horizon and light a beacon, visible from the next hilltop inland, so they could light theirs, which was visible from the next one, and so on. Limited information could be carried this way, but it had the potential to propagate faster than any horseback courier could gallop with a more complex message.
The PSTN telephone network
The invention of the telephone system made it possible to send a message down copper wires via analog signals, with the sound converted in the microphone of the handset to an electrical signal of continuously changing frequency and amplitude which was decoded back to audio via a mic in the receiver. This replicated the speakers’ voice directly into the ear of the listener, with pretty good fidelity — an amazing breakthrough, enabling callers to actually talk to each other directly, and send messages without effective delay, of any content or complexity.
You can do similar things via radio signals of varying wavelengths — the quality of the transmission depends on lots of factors including the quality of the signal and interference factors.
Then in the 1990s these protocols were joined by early mobile telephony, then a network of satellite coverage, initially for military intelligence, but available at a price to civilian networks. Between the different technologies, it became pretty much possible to call anyone anywhere, somehow or other — but frequently this involved poor analog signal quality, delays for connection and relays, and in many cases very high costs indeed.
A new network
But the 1990s also saw the arrival of a brand-new way of communicating, whose costs and connectivity did not depend on distance. A new backbone of information transmission through a network, which meant that the signal could route over any path to reach its destination without delay. While early adopters were chattering at high speed into brick-like mobile phones and watching their per-minute tariffs rack up, another set of geeks was emailing and sending written Usenet messages for almost-free around the world, via their big clunky desktop computers.
Then in 1995 an Israeli company called VocalTec created a product called InternetPhone, an application which offered computer-to-computer calls using speakers and a mic. This was the original proof of concept for VoIP, though it took a long time to catch on, as it depended on very specific set-ups being employed on both ends of the call. At that time internet adoption was very limited, and just like email — the incessant volume of which we take for granted today — the network effects grew slowly at first.
But the transition was inevitable, and in 2003 Skype was founded by Niklas Zennström, from Sweden, and Janus Friis, from Denmark.
The rest, as they say is history, and as the last vestiges of the Skype brand is subsumed within the Microsoft environment, most of the world is nowadays making VoIP calls without even realizing it: via WhatsApp, Facebook Messenger, or using their home Wi-Fi to make calls on their mobile phones.
It is truly the age of VoIP telephony!
But — what IS VoIP...?
VoIP is simply part of the internet, a digital stream of information transmitted over the same Internet Protocol network which circles the globe (and beyond) in 2020.
It involves hardware from much of the old PSTN network, including copper wires, satellite infrastructure, and fiber optic cables, as well as wide and local area wireless networks which bathe us in continual mobile connectivity. Internet data can move through the network via infinite different pathways, meaning it is decentralized and robust. While huge bundles of undersea cables form a backbone of connectivity between continents, the same signals can relay via countless other pathways at need if that goes down, and there are always layers of redundancy and multiple options.
The way your voice call travels this network is fundamentally different than the old analog system, where a dedicated connection had to be established between the two parties for the duration of the call. If you got cut off, that was it — you were left shouting into the void, perhaps without realizing it.
VoIP is digital
With a VoIP call, it’s different.
The voice information is broken down into tiny digital units of information, and these packets are sent out over the internet, then resolved into complete signals at their destination (and converted to sound via a mic close to the listener’s ear, via a technology which may not be that different than the 1950s dial phone).
This process continues in both directions until the call ends, making use of the network’s existence and each packet finding its best route through it, packet switching at need — greatly reducing the possibility of the call disconnecting accidentally.
What do I need to make a VoIP call?
Well, to make a person to person VoIP call today, you really only need a mobile phone connected to a Wi-Fi network — and you do it every time you speak to someone over WhatsApp.
But for your business, you need to understand a little more infrastructure which underpins a phone network.
A Private Branch Exchange (PBX)
This switches your calls between users internally and externally, and acts as the core server for your VoIP system. Once upon a time this would have been a human receptionist or operator, physically plugging in cables to connect one caller with another, but today a system like Ringover’s business cloud phone can offer completely automated transfers, conferencing, IVR and call routing, all driven digitally.
Ringover’s PBX is fully hosted and cloud-based, so you outsource all the responsibility for maintaining and updating it, and you have no up-front costs. No one needs to visit your premises or install physical lines or equipment.
Desk phone, mobile phone, soft phone...?
In addition to a PBX, you will of course also need a phone of some kind!
But in practice what that really means is a device with both a microphone and a speaker, capable of performing that first and last stage of the call — encoding the voice into digital packets, then decoding that back into sound for the listener.
In the past, we had big dedicated lumps of hardware dedicated to this sole function, and you can still operate VoIP calls through a desk phone if this is your preference, indeed for some work environments this might be the best option.
But you are no longer limited to this, and pretty much anything with a speaker or a mic can act as a VoIP phone. The Ringover app can be installed on your desktop, or on your own mobile phone (where it acts completely separately from your mobile network contract and minutes) — the application interface lets you use all the services like voicemail or IVR, as well as any data sources like a phone book or customer relationship management (CRM) integration, wherever you are.
So, when you think of a ‘VoIP phone’, remember this can be anything that receives and emits sounds, and it can be configured to best suit you and the way you work. Provided you are connected to the internet, you can be anywhere at all, which makes VoIP a perfect solution for distributed, growing, or flexible workforces.
Oh, and you can still use your old landline phone if you want to! You’ll just need a VoIP adapter to connect it to your router.
Who can I call with VoIP?
You can call any number, anywhere in the world!
If that number is a traditional PSTN number, the call will route via the internet as far as possible, then via the local network, whether that’s copper wires, a mobile coverage provider, or wireless LAN.
You won’t have to give it a thought, just dial the number, and the call will route and connect via whatever route it can best locate.
What does it cost?
Of course, who you can call will depend on the calling plan you have with your VoIP provider.
VoIP to VoIP calls are frequently ‘free’, in other words they are not metered on a per-minute basis — you pay for a connection for a time period, and can use any amount of data during that time. This makes costs very manageable and predictable for businesses, although pay-as-you-go or pay-as-you-use services are always an option too. Ringover’s simple to understand plans include calls to more than 100 destinations in a single monthly subscription.
Voice in fact uses very low amounts of data compared to transmissions like video, and can get through on pretty slow and basic connections.
Some non-VoIP lines though are simply expensive to connect to, such as premium rate numbers or mobile phone lines in some locations, also other kinds of calls like maritime satellite calls. If you need to call these kinds of numbers, it is usually cheaper to buy a special calling plan from your VoIP provider, for example you might be able to purchase unlimited mobile calling to a specific country for a fixed cost, and even have that call apparently originate from a number in the same location.
How do VoIP phone numbers work?
Back in the day, a phone number was tied to a physical location, and told you about where a call was being made from (even though you probably didn’t have caller ID to see that information when your phone rang). All London numbers once started 01, and when this was changed to 0171 for inner and 0181 for outer London, many were disappointed that their geographical location consigned them non-negotiably to the suburban obscurity — if you were in the wrong street, that meant no central London number for you.
VoIP phone numbers are completely different though, and no longer need to bear any relationship to where the call originates from.
VoIP numbers can be attached to apps on multiple devices, so callers can find you via the app on your mobile phone if you’re away from your desk. Numbers can be assigned to any area code, so that distributed businesses can maintain a sequence of numbers which implies they are all extensions on a network within a building, even though they might be in different continents.
Inbound numbers can even be provided in different locations too, so that customers can make cheap ‘local’ calls to you on familiar-looking numbers, whatever kind of phone they are using. And virtual numbers can be created to protect the real phone number of a caller to protect identity.
The same number can even be used for other kinds of data transfer, like video calls.
So VoIP phone numbers operate completely differently to old-fashioned analog phone identifiers.
However, allocations of numbers and number type (like premium rate numbers which collect revenue for the recipient) are administered differently in different countries and jurisdictions, originating from different legal frameworks which emerged independently — creating complex rules and regulations. So working with a specialist like Ringover is the best way to manage provisioning and functionality internationally.
What about my old number?
Yes, your old PSTN landline or mobile phone number can often be ported into a VoIP network. So you can maintain continuity for your business communications when you transition to a managed cloud phone system, to increase your flexibility, reduce costs, and get ahead of the big switch off coming in 2025.
So, what should I do next?
Are you starting to grasp the potential for VoIP calling to revolutionize your business communications, in scope, cost, and flexibility?
Have other questions about VoIP?
Then contact our experts at +44 20 3808 5555 or sign up for a free trial with Ringover to talk about the best solution for you, from our sole trader plans through to enterprise solutions.