Do internet speed reduced when port(s) closed?

[thankfulWarrior943]

I am living in the University hostel that provide internet connection.
But the speed seems so slow.
When I do port scan, I found that only 443 port that opened. Else are closed.
With thousands of students using the same port (443), does it gonna affect the speed?

Just wonders, because its feel bad when your University close all port, it troubles the students here.