PS, Since you seem to have a fair bit of experience, which software (free or paid) would you recommend as an upgrade/replacement for ivms-4200 (Which is buggy at best!) thanks
May i ask you to expand on what you mean by "Buggy at Best".
From experience, issues with iVMS4200 & viewing/managing multiples of Network Cameras etc, is rarely a software issue.
Many factors can contribute to VMS problems, such as:
1. A gross misunderstanding of the intention of a Video Surveillance System.
2. Sacrificing High Quality Video Recordings for exceptional Live View Images.
3. Some unexplainable delusion an Old "Dell Intel Core i3 Celeron" Laptop you paid $1500 for 10 years ago (just can't let it go), can some how manage processing 8/16/32+ Live Video Streams simultaneously, without popping a hemorrhoid, is just the right device for this task.
4. Ignoring the fact that your 8/16/32+ Live Video Feeds are competing with every other IOT device, including the Teenage Son you can hear in the next room Super Sucking the Network in a Fortnite Rampage, while the wife has got the 80" Smart TV on Netflix, binge watching the latest season of "Bridgerton" ............................. all being negotiated on your network by a "user friendly plug & play" Modem/Gateway your ISP provider sent you.
But hell yeah, i'm sure there is some 3rd Party VMS product out there that can compensate for all of this and more, while fixing the "Buggy at Best" issues your currently experiencing.
Let us know how you go.