What Ports Does RDP Use? A 2025 Guide for ISVs

Remote Desktop Protocol (RDP) is widely used to provide remote access to Windows systems. It’s a default tool in many enterprise environments and a common method for managing remote desktops or servers. But for Independent Software Vendors (ISVs), understanding how RDP works—including the ports it uses—is essential for both functionality and security.

In this article, we’ll break down which ports RDP uses, why it matters, and what safer alternatives exist for ISVs delivering remote application access.

Default RDP Port

By default, RDP uses TCP port 3389.

This port allows the Remote Desktop client to establish a session with the host machine. In most configurations, both inbound and outbound traffic through port 3389 is required for RDP to function properly.

UDP and Additional Port Behavior

In addition to TCP 3389, RDP may also use:

• UDP 3389 – To improve performance for audio, video, and input latency
  
  
• TCP 443 – If using Remote Desktop Gateway or Remote Desktop Web Access
  
  
• TCP 135, 445, and 139 – In some advanced configurations (e.g., printer redirection or shared drives)
  
  

If your RDP deployment is behind a firewall, these ports may need to be manually opened or configured for NAT traversal.

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Security Concerns for ISVs Using RDP

While RDP is convenient, exposing port 3389 to the internet is widely considered a security risk. It’s a common attack vector for brute-force login attempts and ransomware.

Why this matters to ISVs:

• Customers using self-hosted RDP setups may face vulnerabilities
  
  
• Applications delivered via RDP often lack fine-grained access control
  
  
• Licensing RDS properly is often overlooked, creating compliance issues
  
  
• High maintenance overhead for endpoint configuration and updates
  
  

These risks make RDP unsuitable for many ISVs looking to deliver a polished, secure cloud experience.

A Safer Alternative: GO-Global

ISVs that want to deliver Windows applications remotely—without the security and infrastructure burden of RDP—should consider GO-Global.

Why GO-Global is a better fit:

• Doesn’t require port 3389 or RDS
  
  
• Uses secure, browser-based access—no local client or firewall changes needed
  
  
• Built-in session encryption and access control
  
  
• Optimized for publishing applications—not full desktops
  
  
• Simple deployment with less surface area for attack
  
  

For ISVs offering remote access to customers or field teams, GO-Global eliminates the need to expose risky RDP ports while improving user experience.

Final Thoughts

Port 3389 is the default for RDP—but opening it to the internet creates serious vulnerabilities. For ISVs managing remote deployments or delivering customer-facing software, relying on RDP can introduce unnecessary complexity and security concerns.

Instead, consider a more modern approach like GO-Global, which offers secure, RDP-free access to Windows applications—no full desktops, no open ports, and no compromise.

Are you an ISV exploring cloud-based application delivery? Contact us to learn how GO-Global can help you streamline software access for your end users. Or download a free trial to test it yourself.