Port 3408: BESApi — A Registered Port Nobody Remembers

Port 3408 is a registered port with a paper trail that leads somewhere interesting and then goes cold.

What Range This Port Belongs To

Port 3408 sits in the registered port range (1024–49151), also called user ports. Unlike well-known ports (0–1023), which require root/administrator privileges and are home to foundational Internet services, registered ports are available to any application after registration with IANA.

The registration system exists to prevent collisions — two applications both deciding to use port 3408 would be a problem. IANA maintains a registry so that software vendors can claim a port number as their own. Claiming a port doesn't mean anyone uses it. It means someone once thought they might.

What's Listed for Port 3408

Two entries appear in various port databases:

BESApi — registered with IANA in February 2002. "BES" most likely refers to BlackBerry Enterprise Server, the software that powered corporate BlackBerry deployments through the 2000s. BES was the backbone of corporate mobile communication — it sat between your company's email servers and BlackBerry devices, encrypting and routing messages through BlackBerry's infrastructure. An API port would have allowed management tools to talk to the BES service programmatically.

ISSAPI / POWERpack API Port — listed in secondary databases, attributed to a source called Bekkoame. This appears to be an independent or competing claim, and no primary documentation survives to explain what POWERpack was.

Neither entry can be confirmed in detail. BlackBerry Enterprise Server's documented port list focuses on other numbers (3101, 3200, 5096), and 3408 doesn't appear prominently in any BlackBerry technical documentation that still exists online. The registration is real; the service behind it has faded.

Where This Port Stands Today

IANA currently shows port 3408 (both TCP and UDP) as unassigned.¹ Whatever registration existed in 2002 has been vacated or superseded. BlackBerry's enterprise server business declined sharply after 2013 and the software was eventually discontinued.

If you see traffic on port 3408 on a modern system, it isn't coming from anything related to its historical registration. It could be:

• An application that picked the number arbitrarily
• A scanner or probe looking for open ports
• A misconfigured or custom service

How to Check What's Listening on This Port

Linux / macOS:

# Show what process is bound to port 3408
sudo lsof -i :3408

# Or with ss
sudo ss -tlnp | grep 3408

# Or with netstat
sudo netstat -tlnp | grep 3408

Windows:

# Show listening processes
netstat -ano | findstr :3408

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

If nothing comes back, nothing is listening. That's the expected result on most systems.

Why Unassigned Ports Like This Matter

The registered port range contains 48,127 numbers. Not all of them are spoken for, and many that were registered decades ago now sit dormant — companies dissolved, projects abandoned, software deprecated. These gaps matter because:

They're available. A developer building something new can register an unused port and get a stable number that won't collide with established services.

They're not protected. Any application can bind to an unassigned port without permission. This is why unassigned ports in active use often become a security concern — there's no guarantee of what's actually running.

They're historically interesting. Each dormant registration is a small fossil record of the software landscape when it was filed. Port 3408, registered in February 2002, is a timestamp from the era when BlackBerry ruled corporate mobile communication and companies registered API ports with confidence that their platforms would last.

They didn't. The port remains.