Port 2933: 4-TIER OPM GW — Registered, but Rarely Seen

What This Port Is

Port 2933 sits in the registered port range (1024–49151). Unlike the well-known ports below 1024 — where HTTP lives at 80, SSH at 22, DNS at 53 — registered ports don't require root privileges to open. They're claimed by applications and services through IANA's registration process, which anyone can apply for.

Port 2933 has a name in that registry: 4-tieropmgw, short for "4-TIER OPM Gateway."¹ Its companion is port 2934, the client side of the same system, registered as 4-tieropmcli (4-TIER OPM Client). Both were registered by the same contact, Francois Peloffy.

What exactly 4-TIER OPM is — and whether it was ever widely deployed — is unclear. There are no public RFCs documenting the protocol, no open-source implementations, no forum posts from people troubleshooting it. The registration exists; the software, apparently, does not have much of a public footprint.

This is more common than you might expect. The IANA registry contains hundreds of registrations for products that were once important to their creators but never achieved broad adoption. The name gets claimed, the product ships or doesn't ship, and the port sits quietly in the database for decades.

What the Registered Port Range Means

The 1024–49151 range is where most application-layer services live. It's big enough — over 48,000 ports — that collisions are rare when registrations are made properly.

The registration process asks for a service name, description, transport protocol, and point of contact. IANA doesn't validate whether the software actually works or is widely used. The registry is a coordination mechanism, not a quality filter.

This matters when you're trying to interpret what's listening on a registered port. The port number alone tells you what someone intended to run there, not what's actually running there.

If You See Traffic on This Port

If you encounter traffic or a listening process on port 2933, it almost certainly isn't the 4-TIER OPM Gateway. More likely explanations:

• A custom application chose this port opportunistically
• A development server picked it to avoid conflicts
• Malware or a port scanner is probing the range

To see what's actually using it on your machine:

# macOS / Linux
sudo lsof -i :2933

# Linux (alternative)
ss -tlnp | grep 2933

# Windows (PowerShell)
netstat -ano | findstr :2933
Get-Process -Id (Get-NetTCPConnection -LocalPort 2933).OwningProcess

The output will tell you the process name and PID. From there you can identify whether it's something you installed intentionally.