It worked yesterday. Calls were coming in and going out just fine. Now, all of a sudden, it’s stopped working (or The Quality Is Bad, or They Can’t Hear Me, etc...) and I didn’t change anything!
Changes can happen upstream, off the Teliax network, but within the route of your call (Point A to Point B) that can affect call quality and completion.
Aside from that, the world is a mysterious place where software and hardware fall prey to rare solar flares, cyber gremlins, and yes, even well-meaning co-workers or friends trying to turbo-charge your set up.
Here's a list of possible culprits:
Like your PC, PBX’s and other SIP or IAX devices can benefit from a fresh start (i.e., a reboot). When a system runs for a long time, especially under heavy use, corrupted code can get written to memory. Rebooting can resolve this. Moving your PBX or SIP device near a microwave or other device with high RF can also have mysterious and deleterious consequences.
There are millions of lines of code colliding (Interacting) as different systems come together to communicate. With this comes the possibility that a set of code (call them the Sharks), doesn’t get along with a set of code (lets say, the Jets), and when all is said and done, the turf where they engaged doesn’t look the same in the aftermath and a configuration has been ‘mussed up’ or changed.
Upgrades or patches to software (An operating system, server or proxy software) rarely come without bugs. These bugs can take time to notice, identify and squash (by the programmers of that software). In the meantime, what you see is a system that was working yesterday, but not working today. This can also happen with hardware upgrades and tweaks.
So, what seems like a poltergeist or conspiracy can have a rational explanation. We tell you this to ease your tension when you’re researching our Knowledge Base, then calling Support when something "happens to your system,” even-though nobody (that you know of) did anything to it.