The world of telecommunications (TC) differs considerably from that of information technology (IT). I have been doing IT for a while now and I am always surprised at how much the concepts differ between the two spheres.
ISDN PBXs - my first experiences
I got my first PBX system through a Telekom voucher in the 90s in Berlin. I switched to ISDN and received a starting credit of 1,000.00 Deutsche Marks from Deutsche Telekom. To match the credit, I was able to purchase a Quante ISDN PBX for up to 4 terminals for DM 980.00.
After Quante, I stopped off at Auerswald, Sedlbauer, AVM and a few others. After all, Ron Sommer promised us in Germany the wonderful advantages of high-speed connectivity. And yes: I was able to send faxes, make Internet connections, switch calls, set up forwarding and experience with friends how entire call centres could productively handle high-priced ISDN PBXs. A long time ago.
VOIP - the other PBX
At the same time, I got to know companies that were playing in the new world of Voice over IP. Snom, Readytophone, Elmeg and Swyx. My research in the free and open source area finally led me to Asterisk and Digium. VOIP comes from the IT side. Everything via TCP and UDP. So with IP addresses and Internet protocols - fax (emulation) and night switching, because these are concepts that the world of telecommunications has implanted in the heads of companies and specialised experts over the years.
The bet was on and the outcome was actually clear due to the home run of the internet. ISDN is switched off and IP wins. Or on the voltage from above: TC loses out to IT. In 2020, the last ISDN connections for business customers are to be switched to All-IP.
We can find that stupid (and yes there are good reasons to find that stupid), but it is a fact and the winner is decided.
Construction kit vs. commodity
Telephoning is a commodity today. Everyone offers it. Whether Aldi Talk, Vodafone or Magenta. The distinguishing features are small and they all supposedly offer the same thing. For one's own mobile connection, at the end of the day it's more about network coverage.
In the workflows for a company connection, we are dealing with more complex issues. Which number should reach whom and why? How long does a call to support take? Is it even a legitimate call? What happens if colleagues cannot take the call? Should an answering machine be switched on or should a busy signal sound? How do we deal with public holidays or company holidays? Do we have our own telecom room or do we rent one somewhere? What happens if there is a request for video or screen sharing in the telecom room? The central control element of Asterisk is the dial plan, which defines sections and extensions and the actions depending on the input.
As Asterisk itself does not provide a graphical user interface for the administrator, we use the open source software FreePBX as a user interface via web. It comes with all the components of Asterisk as a basis for installation. This means that all the functionalities are available that are also offered by full-blown, high-priced systems from commercial manufacturers. Hundreds of terminals can be connected.
The world and its requirements have become more complex. It is good that IT has won over TC!