Port Number: 1368
Transport Protocol: TCP/UDP
Registered Service: SCREENCAST
Status: Registered but effectively obsolete
What This Port Does
Port 1368 is officially registered with IANA for "SCREENCAST"—a screen sharing or screen casting protocol.1 The registration exists in the official port registry, which means at some point, someone built a screen sharing application and requested this port number for it.
But here's the truth: almost nobody uses it anymore. If you search for technical documentation about the SCREENCAST protocol that runs on port 1368, you'll find very little. The protocol itself has been lost to time, replaced by modern screen sharing technologies that don't need dedicated port numbers.
The Screen Sharing Wars
Port 1368 is a relic from an earlier era of network protocols—a time when every application that wanted to share data over a network would register its own port number with IANA and build its own protocol from scratch.
Screen sharing technology moved on. Today's dominant protocols include:
- Miracast (launched 2012) — Uses Wi-Fi Direct, not a fixed port number
- Google Cast (launched 2013) — Works over standard web protocols
- AirPlay — Apple's proprietary screen mirroring
- Web-based solutions — RTC, WebSockets, HTTPS
None of them use port 1368. The SCREENCAST protocol that was registered here didn't win the screen sharing wars. It didn't even make it to the finals.
What "Registered Port" Means
Port 1368 sits in the registered port range (1024–49151). These are ports that IANA assigns to specific services upon application.2 Anyone can request a port number for their protocol or application. IANA reviews the request and, if approved, adds it to the registry.
Getting your port registered doesn't guarantee success. It just means you asked for a number and got one. Port 1368 is proof that registration and relevance are not the same thing.
What Might Be Using This Port
On most systems, port 1368 is closed. Nothing is listening. The protocol it was registered for has faded into obscurity.
However, because the port is rarely used for its original purpose, you might occasionally find:
- Custom internal applications — Companies sometimes repurpose registered-but-unused ports for internal tools
- Legacy screen sharing software — Extremely old screen casting applications might still use this port
- Malware — Unused ports are sometimes exploited by malicious software precisely because they're not monitored
How to Check What's Listening
On Linux or macOS:
On Windows:
If nothing returns, the port is closed. If something is listening, you should know what it is—because it's probably not the original SCREENCAST protocol.
Why This Port Matters
Port 1368 doesn't matter because of what runs on it. It matters because of what it represents: the graveyard of protocols that didn't make it.
The Internet's port registry is full of these—services that were registered with hope, built with ambition, and then replaced by something better. Port 1368 is a monument to a protocol that lost the screen sharing wars. The registration remains, but the protocol is gone.
That's how technology works. The winners get remembered. The losers get port numbers that nobody uses anymore.
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