Q7 /20 Which TCP port number of the server the Web browser will connect to when specifying...

The URL scheme is http://, which uses the default TCP port 80 by default. The query parameter port=123 is application-level data passed to the server's CGI script and does not affect the transport layer connection port. Port 21 is for FTP, port 123 is for NTP, and port 443 is for HTTPS—none of which apply here.

Step-by-step Derivation:

1. Parse the URL: http://ftp.example.jp/index.cgi?port=123
2. Identify the scheme: http (not https, ftp, etc.)
3. HTTP uses the default port: 80
4. The query string ?port=123 is parameter data sent to the CGI script on the server, not a port directive
5. The browser connects to port 80 and requests /index.cgi?port=123 from that server