Who is the weak link in the chain? Router (mikrotik) - hotspot server (i5 laptop) - Denver - site code?

Question

Highload

Good afternoon)
There is the following system:
Laptop (HP on core i5, win7) - connected by cable to the Mikrotik router (RB951Ui-2HnD)
Phones are connected to the router via WiFi.
The task is to distribute to phones a small site that is raised in Denver on a laptop.
There is no Internet in this system at all.
The role of the hostpot is very simple, no authorization occurs, but simply at the first access, the Mac address of the phone is transferred to the site authorization system, and a redirect to the site itself.
When tested on 10-15 phones, everything was fine, the site loaded quickly, and functioned well on both phones and the admin panel on the laptop itself.
Yesterday there was a test for 70 phones (they connected almost simultaneously, within 1-3 minutes all), and the system instantly hung for everyone, still at the stage of connecting to wifi and first entering the site.
The browser was not responding on the laptop either.
The processor load (according to the task manager) on the laptop was about 10-25%, no more.
The CPU usage on the router was also about 10-15%.
But it was impossible to open the site.
Please help, my knowledge in system administration is not great, but I need to solve the problem.
Who is the weak link in this scheme, which is why everything hangs so tightly?
And what exactly hung, and how to understand it?
How to improve the system?

Answer 1

So far, only one piece of advice: "Put the dusty skeleton of Denver in the closet." All the same, it is for local testing, and not for combat work. Install either WAMP or OpenServer