A company I did some work for had an "AASTRA" VOIP PBX that they decided to decomission so I brought it home.

You can see it here: Re: Using XT-IDE on 386 with Compact Flash larger than 512MB - My tests.

Turned out its' built on a "PC compatible chassis" which ran XP internally. Perhaps your PBX is set up in a similar fashion.

Although the're normally never used, it has Ps2 keyboard/mouse ports and a VGA output (If no Ps2 ... perhaps USB might work on yours?)

If you connect a monitor and keybaord, you can actually see it boot and that it has a BIOS you can enter.

It had an internal proprietary 1-2G flash card, but underneath that was an CF socket. There was no obvious way to "install" an OS, but turns out it did recognize and boot from a USB floppy drive (maybe a bootable stick would have worked as well - I never tried).

I put a CF card in it and was able to installed DOS booted from floppy. I was able to find a packet driver that works with the built in network interface.
The BIOS does recognize USB sticks and presents them to DOS as hard drives.

So it has become a fairly useful little super-quiet DOS system (no fans or spinning rust).

Hopefully you can make use of yours in a similar way!

Nice. Looks like Stratagy is a Toshiba brand.
Some earlier models 4/6/24 http://pdf.textfiles.com/manuals/TELECOM-S-Z/ … nt%20Manual.pdf were normal PCs with a bunch of two port modem ISA cards. Yours seem to have 4 ports integrated right on the mobo, this suggests they made it more of an embedded system / less a PC.

Can you take some pictures of insides?