Which protocol uses TCP port 3389 and UDP port 3389 for remote desktop connections?

Which protocol uses TCP port 3389 and UDP port 3389 for remote desktop connections?

• A. Remote Desktop Protocol (RDP)
• B. Secure Shell (SSH)
• C. File Transfer Protocol (FTP)
• D. Hypertext Transfer Protocol (HTTP)

Answer: (A)

Remote desktop traffic over Windows relies on a protocol that by default listens on port 3389. The main session data travels over TCP, and in modern implementations UDP on the same port (3389) is also used to improve responsiveness in some network conditions. This combination—Remote Desktop Protocol using TCP 3389 and UDP 3389—is what enables GUI remote access with better performance. SSH, FTP, and HTTP serve different purposes and use different ports: SSH is for secure command-line access on TCP port 22; FTP manages file transfers on ports 20/21; HTTP handles web traffic on ports 80/443. None of these provide a remote desktop GUI over both TCP and UDP on port 3389, so the protocol described is Remote Desktop Protocol.

Remote desktop traffic over Windows relies on a protocol that by default listens on port 3389. The main session data travels over TCP, and in modern implementations UDP on the same port (3389) is also used to improve responsiveness in some network conditions. This combination—Remote Desktop Protocol using TCP 3389 and UDP 3389—is what enables GUI remote access with better performance.

SSH, FTP, and HTTP serve different purposes and use different ports: SSH is for secure command-line access on TCP port 22; FTP manages file transfers on ports 20/21; HTTP handles web traffic on ports 80/443. None of these provide a remote desktop GUI over both TCP and UDP on port 3389, so the protocol described is Remote Desktop Protocol.