Signing you in…

Ports and Sockets

A socket is the API endpoint: (IP, protocol, port) on each host. Ephemeral ports (high range) are chosen by the OS for outbound connections; servers bind well-known ports (80, 443, 22). NAT rewrites these tuples — why two peers behind NAT need relays.

Client connects to server
TCP connection
💻Client :ephemeral
🖥️Server :443
🔄NAT box
Content is available with subscription.
Get full access to all courses on the platform for one year with a single payment.
Unlike other platforms that charge per course, here you get everything for one price, and after one year of use there will be no automatic charge for the following year.