Hello, this may be a really beginner question, but I really want to make sure I'm going in the right direction before investing time in this. Heres what I have.

$ORIGIN charlieli.me.
$TTL 1800
charlieli.me. IN SOA ns1.digitalocean.com. hostmaster.charlieli.me. 1441944900 10800 3600 604800 1800
charlieli.me. 1800 IN NS ns1.digitalocean.com.
charlieli.me. 1800 IN NS ns2.digitalocean.com.
charlieli.me. 1800 IN NS ns3.digitalocean.com.
charlieli.me. 1800 IN A 45.55.33.185
fileserver.charlieli.me. 1800 IN A 45.55.33.185

fileserver.conf

<VirtualHost *:80>
    ServerName fileserver.charlieli.me
    ServerAdmin charlie.li@carleton.ca
    ServerAlias fileserver.charlieli.me
    DocumentRoot /var/www/fileserver
    <Directory /var/www/fileserver>
        # enable the .htaccess rewrites
        AllowOverride All
        Require all granted

    </Directory>

    ErrorLog ${APACHE_LOG_DIR}/error_orlybg.log
    CustomLog ${APACHE_LOG_DIR}/access_orlybg.log combined

</VirtualHost>

My primary domain's virtual host is 45.55.33.185 port 80, my subdomain fileserver.charlieli.me is also configured to 45.55.33.185 port 80.

On my subdomain, I would like to open a web-socket to send files to store and retrieve remotely. In my configuration for the landing site, it's configured to port 80, does this mean I have to listen/receive/respond through port 80 or could I specify another port on the subdomain like 9090 top open with my websocket program and receive data from fileserver.charlieli.me:9090?

Does the "Virtual Host" address in my conf really mean both my primary and subdomain is really sharing the same set of ports and I can access my 9090 port even from charlieli.me:9090 rendering a subdomain redundant?