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Fundamentals

Understanding how remote desktop protocols work helps you choose the right one and troubleshoot issues effectively.

What is a Remote Desktop Protocol?

A remote desktop protocol transmits:

  1. Display data - Screen contents from server to client
  2. Input events - Keyboard and mouse from client to server
  3. Clipboard - Copy/paste between systems
  4. Audio - Sound from server to client (some protocols)
  5. Devices - USB redirection (some protocols)

The Three Protocols

VNC (Virtual Network Computing)

Originally developed at AT&T Cambridge Laboratory in 1998. VNC uses the RFB (Remote Framebuffer) protocol.

How it works:

  • Captures raw framebuffer data
  • Sends pixel differences to client
  • Simple protocol, works everywhere
  • No audio or USB by design

RDP (Remote Desktop Protocol)

Microsoft's proprietary protocol, released with Windows NT 4.0 Terminal Server in 1998.

How it works:

  • Sends high-level drawing commands (not raw pixels)
  • Client reconstructs display locally
  • Much more efficient for typical desktop work
  • Full multimedia and device redirection

SPICE (Simple Protocol for Independent Computing Environments)

Developed by Red Hat, initially for virtualization environments.

How it works:

  • Designed specifically for VMs
  • Agent runs inside guest OS
  • Can leverage VM host for optimization
  • Excellent USB and display features

Learn More