<span>Ports are used to distinguish among multiple destination processes in a single host computer.</span>
UDP (User Datagram Protocol)<span> port 500 is used for i k e traffic from VPN client to server.
</span><span>This port is used during the establishment of secure VPN tunnels.
</span>
The CPU is the working principle
Lookup the isalpha() function in the C standard library, this function will check and return non-zero for alphabetic characters.
