Kind of like a Swiss army knife, the raspberry pi can turn into anything. If MacGyver was still on TV, he'd use one.
In this case a PBX micro server. Steel case, well made.
HDMI port is clearly accessible, but on a PBX, you'll more than likely be running headless. Or there is the composite out...
It is a small box, barely bigger than the Pi, and smaller than all the acrylic cases I've seen. I'll have to add a little powered speaker to the headphone jack, comes in handy in this scenario, to get audible alerts.
There is even a cutout to see the LEDs for power, network etc.
I'm going to add this 4 line LCD display for caller ID, showing how many messages etc.
This is not the typical 16 pin display. This is a Samsung unit with 9 pins. I dont have the specs, but I'll dig. All I know is that it came from a GE phone, to display caller ID, so very a propos on a PBX!
In the interim, this Pi has been running as a PBX for a month now, but I just got the case for it today. The Raspberry Pi is a perfect match for this, at least for my application. I have no problem running two lines on this.
Almost forgot to mention, you can of course install asterisk, freepbx etc on raspbian (that is how I started, but I just switched recently), or you can go an easier route, use one of these two distribution (play around with both and choose one):