Port 3370: satvid-datalnk — A Name Without a Protocol

The Registration

Port 3370 sits in the registered port range (1024–49151). These ports are assigned by IANA, the organization that coordinates the Internet's naming and numbering systems. Unlike the well-known ports below 1024, registered ports don't require elevated system privileges to open—any application can use them.

IANA lists port 3370 as part of a five-port block (3367–3371) assigned to satvid-datalnk: Satellite Video Data Link. The registration contact traces to Scott Engel at an Intel email address (ccm.jf.intel.com, Intel's Hillsboro, Oregon campus). TCP and UDP both carry the designation.¹

That is the entirety of what exists publicly about this protocol.

There is no RFC. No technical specification. No open-source implementation. No deployment guide. Whatever Intel's satellite video data link project was, it either never shipped, never used these ports in practice, or quietly moved on without updating the registry.

What This Means in Practice

The IANA registry is not a live inventory of what's running on the Internet. It's a reservation system—and like hotel reservations, ports can be reserved without anyone ever checking in.

Port 3370 is registered but functionally unclaimed. If you see traffic on this port, it isn't satvid-datalnk. It's something else: a custom application, a game server, a development service, or occasionally malware using an obscure port number precisely because nothing legitimate is expected there.

How to Check What's Using This Port

If port 3370 is open on a machine you manage, find out what's holding it:

macOS / Linux:

# Show the process listening on port 3370
sudo lsof -i :3370

# Alternative using ss
ss -tlnp | grep 3370

Windows:

netstat -ano | findstr :3370

The output will show the process ID (PID). Cross-reference that with Task Manager or ps aux to identify the application.

Why Ghost Registrations Exist

The registered port range operates on good faith. Organizations request port assignments, IANA records them, and the expectation is that the protocol eventually becomes real. Sometimes it does. Sometimes a project is cancelled, the team moves on, and the reservation sits in the registry indefinitely—a five-port tombstone for a satellite video system that never shipped.

This isn't a flaw. The registered range is large enough (48,127 ports) that ghost registrations don't cause real harm. They're artifacts of how the Internet was built: optimistically, by people who believed their project would matter enough to need a permanent address.