This could be wrong or could be right. I do not know, but what I have seen is that since the COVID-19 pandemic started, businesses have been struggling with how to get the income. Sadly, some indispensable businesses know their status and they have started to impose new fees. The telecommunication industry is no exception; since November 2020 at some point, carriers started to apply a short call policy with a fee. If the policy already existed and not enforced, I can't tell, but what I can is the charge. If you ask one of them why the charge, they will answer they try to stop dialers. Again, nobody can tell if this is the real reason.
Fortunately, a short call definition for everybody is any answered call that is six or fewer seconds in length. When a call is terminated (outgoing call made), if the callee answers and the call is hung up before 6 seconds, the fee applies. There are two possible scenarios:
If you are into Linux and Photography (some of us are) and you, like me, have a not very old Canon camera, you may see that the RAW files are not longer CR2 files, but with extension CR3. CR3 raw format is the new replacement for CR2 that comes with all Digic8 chipsets. In my very specific case, with my Canon 90D.
I was amazed by the quality of this camera (I come from a Canon 200D aka SL2 that has a Digic7 chip). Canon did a good job from version 7 to 8. However, here it comes the issues, I saved my photos in CR3 format, and when going to my desktop, not KDE, nor Darktable (current version 3.2.1 when writing this article) were able to recognize it. Windows is not an option for me.
A Class 4 PBX? What it is? In short, a class 4 PBX is the one that interconnects different PBX. It is very common that this class of PBX doesn't have contact with end-users. The perfect example of class 4 PBX is the carrier that sells IP telephony companies the DID's (origination) and outgoing gateways (termination). There are more differences between a 5 class and a 4 class PBX, my article about that covers it.
For the sake of this article, let's pretend everybody knows what is a class 4 and a class 5 PBX. Let's discuss FusionPBX. FusionPBX, out of the box brings let's say, 90% of all the needs a class-5 PBX needs: voicemail, IVR menus, time conditions, queues, and a lot of more features that are useless if all you want is a class 4 PBX.