Port 1875: Westell Stats — A Registered Port from the DSL Era

What Port 1875 Is

Port 1875 is officially registered in the IANA Service Name and Transport Protocol Port Number Registry as westell-stats, assigned to Westell Technologies. It operates on both TCP and UDP. No public protocol specification exists — no RFC, no technical documentation. It was registered for internal use by a specific company, for a specific product line, in a specific era of the Internet.

That era is over.

Westell Technologies

Westell was founded in 1980 in Willowbrook, Illinois, building equipment for telephone lines. In the 1990s, they pivoted into DSL — the technology that let ordinary copper phone wire carry broadband Internet. At its peak, Westell shipped millions of DSL modems and gateway routers to American homes, mostly through partnerships with telephone companies rolling out broadband service.¹

Port 1875 was registered during this period, almost certainly for some form of device telemetry or statistics reporting — a modem phoning home with performance data, error rates, or diagnostics. The kind of internal plumbing that shipping products at scale requires.

In April 2011, Westell sold its networking product line — the modems, gateways, and routers — to NETGEAR.² The products moved. The port registration stayed. It now sits in the IANA registry, a forwarding address for a business that already left.

What This Range Means

Port 1875 falls in the registered ports range (1024–49151). These ports are not freely claimed — any organization that wants to officially register a service submits a request to IANA, which maintains the registry. Registration doesn't mean a protocol is public or standardized. It just means someone said "we use this" and IANA wrote it down.

Registered ports are a middle zone:

• Below them (0–1023): well-known ports, assigned to foundational protocols — HTTP, SSH, DNS, SMTP
• Above them (49152–65535): dynamic/ephemeral ports, used temporarily for outbound connections and never registered

Most of the 48,000+ registered port entries are like port 1875: legitimate reservations made by real companies for real purposes, most of which you'll never encounter on a modern network.

Is Anything Actually Using This Port?

Almost certainly not in any meaningful way. If you see traffic on port 1875 on your network, it's not Westell stats — that product line is gone. Possibilities:

• Custom application: A developer or sysadmin picked an obscure registered port because it seemed safely out of the way
• Scanning or probing: Port scanners sweep entire ranges looking for open ports
• Malware: Malicious software sometimes uses non-standard ports to avoid detection

How to Check What's Listening

If you want to see whether anything on your machine is bound to port 1875:

macOS / Linux:

lsof -i :1875

or

ss -tlnp | grep 1875

Windows:

netstat -ano | findstr :1875

The process ID in the output will tell you which application opened the port. Cross-reference it with Task Manager (Windows) or ps aux (Unix).

Why Unoccupied Registered Ports Matter

The port space isn't infinite, but 65,535 is large enough that most of it sits empty. Abandoned registrations like port 1875 create a kind of port archaeology — evidence of companies, products, and network assumptions from a different era of the Internet.

They also create real operational considerations. When you're configuring a firewall or running a service, choosing a registered-but-dormant port is safer than choosing a port that might conflict with something actively used. Port 1875 is quiet. It's unlikely to collide with anything you care about. That makes it a reasonable choice for internal tools — just document what you're using it for, because the IANA registration no longer tells the story.