3CX PBX for Windows: Everything you ever wanted from a phone system
Review Back in the 1990s when I started to work with telephone and voicemail systems it was all pretty straightforward: install some analogue or ISDN lines and write a vast cheque for a PBX.
This meant, in my case, an Alcatel 4400 and an Octel Serenade voicemail server. The handsets were digital, though proprietary, and connected by the structured cabling of the office.
Since then, things have changed radically. Handsets are mostly no longer proprietary and are able to work with standards-based Voice over IP (VoIP) protocols such as SIP and RTP.
Power over Ethernet is now commonplace and inexpensive, and the average IT manager's understanding of how VLANs work makes it a relatively simple job to install a modern phone system.
Asterisk the leader
In 1999 Asterisk was born. This is an open-source VoIP system that you can run up on pretty much any PC you find lying in a cupboard. It operates as a fully fledged PBX, entailing no cost aside from the hardware and the phone lines you plug in.
Helpfully, Asterisk's creator Digium is a vendor of Asterisk-supported ISDN and analogue hardware, so connecting Asterisk to the public telephone network is not a problem.
For a number of years, then, we had two parallel streams: hardware-based PBXs and software-based ones. If you were a corporate and you wanted a super reliable phone system, you went for something like a Mitel 3300 ICP or a Cisco Unified Call Manager (CUCM). And if you wanted something cheaper but with a less bullet-proof reputation, you chose the software option.
The virtual route
In the past few years, however, the hardware vendors have taken that extra step. So if, for instance, it is time to upgrade your Mitel 3300 ICP, you have the option of running it as a virtual appliance on a VMware ESXi hypervisor.
The same goes for the CUCM – unsurprising given that a CUCM controller is really just a PC with a blue-green bezel on the front.
There is just one problem with moving to a software-based PBX: how to connect with the public telephone network and with your internal analogue fax machines and modems.
In some cases (such as with Asterisk) you can have on-board public switched telephone network (PSTN) hardware that is addressed directly by the software. In most cases, though, it means having an external device for either function or both.
I recall being asked once by a senior manager: “Why don't we virtualise our Mitel 3300?” Answer: because we could chuck away one box but we would have to introduce an ISDN-to-IP box for the PSTN and an analogue-to-IP box for the fax machines, doubling the number of boxes we would be supporting.
Take a SIP
Public telephone services are starting to emerge from the Dark Ages and service providers are beginning to offer PSTN services using SIP on an IP-based circuit as an alternative to ISDN.
At present SIP services are mainly provided by third parties trying to compete with the traditional PSTN suppliers. The problem is that if the PSTN provider starts to sell a SIP service it screws up its revenues because competition forces it to sell it much more cheaply.
I live on a small rock in the Channel Islands and I know that while both of our local main telcos have SIP capabilities, neither has yet figured out how to “productise” them (their word, not mine) without seeing their income dropping like a stone, so I can't actually buy them yet.
In places like mainland UK, Europe and the USA, however, SIP services from newer telcos are now plentiful, so it makes a lot of sense to go for a software PBX. The only legacy consideration it leaves us with is analogue faxes, and since there is vast competition in the internet-based fax market, that is an easy one to work around.
Which software PBX would one choose, then? Well, the Mitel or Cisco ESXi-based offering is a good one, though it can be pricey for licensing (and it assumes you have a virtual infrastructure to sit it on).
And then there is Asterisk, which is free but for some unfathomable reason is still no simple task to configure. Wouldn't it be great if someone addressed that bit of the market that is saying: “Oh, just give me something I can understand with a comprehensible GUI, and which I can run up on a Windows server”.
Rather like the 3CX Phone System, a VoIP-based PBX for Windows, just out in version 12.
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