It's been suggested that I post this here. It isn't exactly a help request but it might be of interest.
It is only distantly related to Plusnet because my employer used to use Plusnet ADSL and BT phone lines, conected to a 1990s era PBX with at its peak maybe 10 phones
The story probably begins in about 2016 when we were stuck with ADSL (not ADSL2) service at about 3M. Given the awful sync speed I hadn't even tried to upgrade.
A coleague somehow organised a BT FTTP service at what seemed like a FTTC price. Not exactly sure how, one story I heard was a nearby Auction house had paid a premium to get their fibre service and by doing so made it available to our area.
Getting it installed was a saga as our lines go via a "composite" pole that isn't suitable for ladder access, requiring a van with a cherry picker. Unfortunately the report was ignored, so the next van turns up with ladders, and the next...
Eventually it is sorted out.
So at this point I had a Plusnet account providing email, and a BT account for fast internet access. I had and still have very little faith in the services connected with the BT account as all the help or information links just went to a customer support page, so although in theory I could use BT for mailboxes it seemed like a really bad idea. It still does.
And my boss has taken a dislike to the telephone system...
So we get visited by a salesman for some other provider
and signed up for a minimum 7 year contract to put in a system with six digital phones. 7 years!!
Barely 2 years in I'm getting annoyed that to add anything we need to go through the provider, everything is locked down. I'm sure I recall the salesman telling my boss he could have a terminal at home, that seems to have been forgotten along the way and the cordless handsets we wanted for our workshop do not integrate well with the system.
NAT traversal is janky, somewhat improved by replacing our router.
By asking nicely I got the SIP password, so by unplugging a terminal I could connect with a softphone, and this worked from home.
I had also taken an old (2010-ish) desktop PC, fitted 8GB of RAM and reformatted it into a Linux server, tried running GITlab and lost interest so the box was going spare. I'd been using a 3CX softphone for testing so it seemed logical to install a 3CX server, to learn the system. I also found out that by switching the port forwarding on the router I could make 3CX handle calls. This was partly out of curiosity and partly in case my boss found a way out of the contract and told the supplier where they could stick it and I needed to pull a new phone system out of a hat.
Then our secretary had a week off and my boss wanted calls to go to his mobile. Since I knew how to switch to 3CX it seemed the easiest way, one mobile app install later the boss is handling incoming calls with me as second in line.
Somewhere around this time my boss got the cloud bug and decided we would migrate to Google. On the plus side we actually managed to migrate our email and domain name so we managed to move without changing domain names. This feels like an achievement. Then again someone enabled domain wildcards and the resulting crawl spam was poluting our Google results for the next two years. Seriously don't turn on wildcards unless you really know what they are meant for.
Then Covid hit and having the ability to take calls from anywhere seemed rather useful so I never switched back to the leased phone system. We bought a couple of phones mainly so we could have something nice on the front desk.
