To go back in time, telephone systems were known as PBX or PABX, which translates to Private Branch Exchange or Private Automated Branch Exchange. All that means is that there was a controller on-site that directed and distributed incoming calls ...
We used terms such as 'hunt groups' which were collections of phones, we had 'extensions' which you could 'direct dial' or if you went even further back, you had a switchboard operator answering the incoming calls, then putting big chunky plugs in sockets to route the call to the right person.
Centrex is short for Central Exchange. BT called this Featureline. Businesses could have the basic functionality of a PBX/PABX including hunt groups, pick-up groups, call divert to internal and external numbers, call hold/transfer and voicemail without the expense of the PBX controller hardware on-site.
All the call routing/switching was done at source, i.e. at the local Telephone Exchange. You had to rent a copper line per user, so if you wanted 10 extensions, you would rent 10 lines, even if most of the desks didn't need to make a call.
The main difference between then and now is the medium by which you can have a Centrex style system. We now call it 'hosted telephony' or 'cloud telephony' or even Voice over Internet Protocol (VoIP) and we use the internet as the medium to connect to software in data centres.
Pricing can vary from £5.00 per month per connected user, up to as much as £25.00 per user per month depending on features. There are currently over 70 commercial VoIP hosted system providers in the UK and you really do need an independent telecoms specialist to understand your business and then find the right system to match your requirements.
You can purchase or rent the actual handsets on desks or opt for softphones (applications that sit on your desktop or an 'app' for your smartphone connected to the office number). Softphones are generally free and rely on a constant internet connection via Wi-Fi or 4g.
There is also, what we call in the industry, 'hybrid' models in the world of telecoms and IT which is a mixture of some equipment/services on-site and some equipment/services 'off-site'. Hybrid systems have evolved out of conventional telephony and offer the type of programming facilities as traditional/conventional PBX/PABX systems and therefore offer much more flexibility in call handling/routing than a hosted service.
The pricing model also differs from a hosted service as you pay per concurrent call, not the number of connected users to the service platform. This is the conventional model similar to that of a PBX. so if you had 10 people and only 5 were going to make and receive calls, only 5 lines need to be rented from your service provider, not 10.
There is lots of confusion in terminology between fully hosted, VoIP and Hybrid Systems (which are also VoIP/SIP) so it is advisable to consult an independent adviser to understand your business first and they can design a product/service that will suit your business and the way in which is the most efficient for you and your team!
Don't let your host take advantage of you. Speak to someone like me first.
If you feel inspired to find out more then do call me on 07555 807700 or leave a comment below and I'll be in touch as soon as I can.