Port 1916: Persoft Persona — A Ghost in the Registry

What This Port Is

Port 1916 is assigned in the IANA registry to Persoft Persona, a product from Persoft, Inc. — a software company based in Madison, Wisconsin that operated from 1982 until its acquisition by Esker S.A. in 1999.¹

The assignment covers both TCP and UDP.

In practice, you will not encounter Persoft Persona in the wild. The software is long discontinued. Port 1916 exists in the registry as a historical artifact — registered, named, and empty.

The Product Behind the Port

Persoft was best known for SmarTerm, a terminal emulator for the IBM PC that let users connect to mainframes and minicomputers from their desktops. By the mid-1990s, the company saw a new opportunity: instead of installing client software on every workstation, what if users could access AS/400 and VAX hosts through a web browser?

In late 1996, Persoft introduced Persona Intranet — a family of Java applets that delivered terminal sessions inside a browser window.² No client install. No IT rollout. Just Java.

It was a reasonable bet for 1996. Java applets were ascendant. Browser-based enterprise software was the obvious future.

The future arrived differently. Java applets were deprecated, then removed. Browser security models tightened. The whole approach became obsolete. Persoft was acquired by Esker S.A. for $5 million in 1999,³ and Persona went with it into history.

Port 1916 stayed in the registry.

What Range This Port Belongs To

Port 1916 falls in the registered ports range (1024–49151). These ports are not reserved for operating system use, but they are tracked by IANA. Companies and developers can formally register a port for their application, which Persoft did.

Registration doesn't mean exclusivity — it's a declaration of intent, not enforcement. Anyone can run any service on any port. But the registry helps avoid accidental collisions between different applications trying to use the same port number.

Who Might Be Using This Port Today

Nobody, in any official capacity.

If you see traffic on port 1916, it is most likely:

• Malware or scanning activity — Port scanners routinely probe all registered ports
• A custom internal application — Developers sometimes pick obscure registered ports for internal tools, knowing nothing else claims them
• Background noise — Automated Internet scanners that sweep the full port range

There is no known modern software that legitimately uses port 1916.

How to Check What Is Listening

To see if anything on your system is bound to port 1916:

macOS / Linux:

sudo lsof -i :1916

or:

ss -tlnp | grep 1916

Windows:

netstat -ano | findstr :1916

If these return nothing, nothing is listening. If something appears, the process ID will tell you what it is.

Why Ghost Registrations Exist

The IANA registry is additive. Ports get registered; they rarely get formally unregistered. When a company shuts down or a product is discontinued, the registry entry persists.

This is mostly harmless. It means the registered ports range contains hundreds of entries for defunct software, abandoned protocols, and products that shipped for one year in 1997 and never again. Port 1916 is one of them.

The alternative — actively purging dead registrations — would require IANA to determine which software is truly gone, contact registrants who no longer exist, and make judgment calls about dormancy. The registry chose consistency over cleanliness. The ghosts stay.