title: Could I use port 443 for my webservice or is this port reserved?
body: <p>I have an app which uses a backend (REST webservice) on a public server. Currently I am using 8080 as the incoming port and asked myself if this is correct. In theory I could choose almost any port. Theoretically... But it is advisable to use a non-reserved port.</p>
  
  <p>I once heard that calling a web service with an "exotic" port could be blocked in a public WLAN. Due to firewall/proxy rules. Could that really happen?</p>
  
  <p>Would it make sense to use port 443 for the web service? (I use a SSL certificate on my backend)</p>