Port 3717: WV CSP UDP/IP CIR — A Registered Port for a Dead Protocol

What This Port Is

Port 3717 is officially assigned to WV CSP UDP/IP CIR Channel — the UDP/IP transport channel for the Wireless Village Client-Server Protocol (WV CSP).¹ It was registered with IANA in March 2003 and operates on both TCP and UDP.

You almost certainly have nothing running on this port. The protocol it was built for no longer exists in any meaningful deployment.

The Brief Life of Wireless Village

In 2001, Ericsson, Motorola, and Nokia formed the Wireless Village consortium. Their goal was ambitious: create an open standard for mobile instant messaging and presence before the market fragmented into proprietary silos.²

The timing made sense. Mobile phones were proliferating. SMS was proving people wanted to communicate from their handsets. But SMS was one-way, fire-and-forget. Wireless Village wanted something richer — presence (knowing if someone was online), group chat, shared content, and real-time messaging, all delivered over the constrained networks of 2001-era mobile devices.

The Client-Server Protocol (CSP) was the core of it. XML carried the protocol primitives. The architecture needed multiple transport channels depending on how the device connected — SMS for one path, UDP/IP for another. Port 3716 handled the SMS CIR channel. Port 3717 handled the UDP/IP CIR channel.³

By 2003, Wireless Village had merged into the Open Mobile Alliance (OMA), and its specs became OMA IMPS 1.0.⁴ Implementations were certified. The ports were registered. It looked like this might actually become the standard.

It didn't. Proprietary systems won — carriers locked users into their own messaging services, XMPP gained traction in some circles, and then the iPhone arrived and made the entire question moot. OMA IMPS became a footnote.

The Registered Ports Range

Port 3717 sits in the registered ports range (1024–49151). This range means:

• The port has been formally registered with IANA by an organization with a specific purpose
• Any process can technically bind to it without special privileges on most systems
• The registration is a statement of intent, not enforcement — nothing stops other software from using this port

The registered range is where most application-layer protocols live. Unlike the well-known ports (0–1023), which require root/administrator privileges to bind and carry the web's essential infrastructure, registered ports are the middle ground: named but not guarded.

Port 3717's registration is now effectively a historical artifact. IANA keeps it listed, which prevents another organization from formally claiming it, but in practice the port is available.

What Might Actually Be on This Port

In the real world, if you see traffic on port 3717, it's almost certainly not Wireless Village:

• Custom application or game using an arbitrary port
• Internal tooling or service with no standard assignment
• Malware using a registered-but-unused port to blend in
• A development server that picked this port for no particular reason

How to Check What's Listening

On Linux or macOS:

# Show what process is listening on port 3717
sudo lsof -i :3717

# Or with ss (Linux)
ss -tlnp | grep 3717

On Windows:

netstat -ano | findstr :3717

The output will show the process ID. Cross-reference with Task Manager or ps to identify it.

For network-level inspection:

# Check if port is open on a remote host
nmap -p 3717 <target-ip>

Why Unassigned-in-Practice Ports Matter

The port registry exists to prevent collisions — to make sure that when two pieces of software want to communicate on a known port, they're speaking the same language. When a protocol dies, its registered port lingers. This is intentional. IANA doesn't reclaim ports because the cost of reclaiming (confusion, potential conflicts with legacy systems) outweighs the benefit. There are 65,535 ports. There's room.

Port 3717 is a small monument to a mobile Internet that almost was — registered with care, used briefly if at all, and now sitting quietly in the registry while the world moved on to protocols its architects couldn't have imagined.