Before I get into the mistakes made part, let me take a moment to talk about the telephony home lab, what my thoughts/ideas were behind it, and why I chose to include a vintage PBX into the mix (short answer – because I felt like it).
In some cases, IT people like myself often run “home labs” (or homelabs if you prefer), basically small (sometimes not so small) IT setups in their home, partially just to tinker and have fun, partially to learn or TRY things , and sometimes providing useful services to the household in the process.
It’s not unheard of, especially for things like networking certifications where getting a couple obsolete routers off Ebay and having them talk to each other gains you knowledge you can still apply today with modern hardware. You can also experiment with stuff, such as taking a network cord and plugging it into 2 switch ports at once to see what happens, while not actually breaking a business-critical production system (that’s for the users to do).
I’ve always loved telephony and combined with my vintage computer/technology interests, I thought a telephony lab would be fun to mess with. Here were my thoughts behind it:
- Use and learn Asterisk; a modern open-source telephony software platform. This includes learning the protocols that Asterisk uses, particularly 2 very popular VOIP protocols SIP and IAX.
- Potentially bridge the lab to modern and/or cloud-based telephony platforms, like 3CX, voip.ms, Twilio, or Azure Communications Services (just to name a few)
- Running Asterisk under Linux means more Linux experience, no matter how much I complain about it sometimes (I love Linux, it just doesn’t always love me back). This may include virtualization or docker (lesson learned – Asterisk doesn’t play well in docker)
- Now for the “why bother” part: connect a modern Asterisk instance up to an old PBX, leveraging some still-used-but-perhaps-fading technologies such as T1, ISDN, and POTS, and get them to talk to each other. See how they interact with the modern protocols, and get to touch and play with real hardware.
- Leverage both Asterisk and the PBX to provide my own modem/dial-up infrastructure, to allow older computers to “call” into each other, or even provide internet access to older computers or other devices like Teletypes and terminals.
- Try some fun experiments, answering questions like:
- Does a PBX, that may be doing real TDM switching, have better connectivity/higher quality/lower latency connections than a sip-connected trunk? (IE will 2 modems calling each other on the PBX connect at a higher rate than 2 modems calling each other through sip-connected ATAs?
- What about if the call stays within a single SIP channel bank?
- Can the telephony lab be bridged to other means of communication, such as radio? After all, the Carterfone decision, based on a device that enabled farmers to use radios to make phone calls, ultimately led to the undoing of ma bell’s monopoly on the communications industry to an extent.
- Share the learned knowledge here on my website and elsewhere, and keep some vintage electronics out of a landfill.
The moral of the story here is you do you; some people prefer to leave work at work, and for the others that play at home, some prefer to keep it strictly educational and modern. I fall into the middle ground; learn and try new things while making it more interesting and challenging by tinkering with older/redundant stuff that may be considered a colossal waste of time and money. Some people buy Legos; I prefer my Legos to have blinky lights.
I’ll end with this: schools teach history for a reason; to truly understand the current is to know it’s past. This applies to all things in life; technology included.