Port 3594: MediaSpace — A Name Without a Protocol

What Port 3594 Is

Port 3594 sits in the registered ports range (1024–49151). These ports are allocated by IANA for specific services and applications — not reserved for the operating system like the well-known ports below 1024, but not freely up-for-grabs either. Any software author can apply to IANA to claim a port in this range for their application.

Port 3594 has such a claim. IANA lists it as assigned to a service called MediaSpace, over both TCP and UDP.¹

The Problem: MediaSpace Is a Ghost

The IANA entry for port 3594 reads:

The description is the name. There is no RFC. No protocol specification. No contact. No date. No documentation of what MediaSpace does, how it works, or who built it.

A 2013 SourceForge project called "MediaSpaces" exists — a Java tool for integrating distributed multimedia data sources — but it has no documented connection to this port and was never widely deployed.²

In practice, port 3594 is functionally unassigned. The registration exists; the protocol does not.

What Might Actually Be Running on This Port

If you see traffic on port 3594, it almost certainly isn't the MediaSpace protocol — because that protocol has no public definition. More likely candidates:

• Custom application traffic — Internal tools and proprietary software often land on obscure registered ports to avoid conflicts with well-known services
• Malware or remote access tools — Unusual ports are sometimes used to blend in or avoid firewall rules; this port's obscurity makes it attractive for that purpose
• Port scanner noise — Automated scans probe every port; seeing a connection attempt doesn't mean anything is listening

How to Check What's Listening

If you need to know what's using port 3594 on a system you control:

Linux/macOS:

# Show the process listening on port 3594
ss -tlnp | grep 3594

# Or with lsof
lsof -i :3594

Windows:

# Show listening ports and associated processes
netstat -ano | findstr :3594

# Then look up the PID
tasklist | findstr <PID>

Firewall / network inspection:

# Check if the port is reachable from another machine
nc -zv <hostname> 3594

If nothing responds, nothing is listening — which is the expected state for port 3594 on most systems.

Why Ghost Registrations Exist

The registered port range has over 48,000 slots. IANA has historically assigned ports on request with minimal verification — someone submits a name, IANA records it, and if the software never ships or the protocol specification never gets written, the entry just sits there indefinitely.³

Port 3594 is one of many such entries: technically claimed, practically empty. The port system is full of these — names attached to nothing, placeholders that never became protocols. They're harmless, but they create a false impression that every port has a story. Some ports have registrations without stories.

This one is quiet.