Port 3629: ESC/VP.net — Epson's Projector Control Protocol

What This Port Does

Port 3629 is assigned to ESC/VP.net, Epson's proprietary network control protocol for projectors. It runs over TCP and UDP, and it's registered with IANA as of October 2002.¹

When a control system (a Crestron or AMX controller, a home automation hub, or even a simple script) needs to command an Epson projector over the network — power on, switch input, query lamp hours, adjust volume — it connects to port 3629 on the projector's IP address and speaks ESC/VP.net.

How the Protocol Works

ESC/VP.net has two modes:

Session mode requires a handshake before any commands are accepted. The controller opens a TCP connection to port 3629 and sends a specific header sequence. The projector responds with its identifier string. Only after this handshake will the projector accept commands. It's the projector's way of saying: introduce yourself first.²

Session-less mode skips the handshake and accepts commands directly — simpler, but not supported on all models.

Commands are compact binary-and-text hybrids. A power-on command looks like:

ESC/VP.net\x10\x03\x00\x00\x00\x00,PWR ON\r

The projector responds with a status acknowledgment. Commands cover power state, source selection, picture settings, error queries, and lamp hour reporting.

Where You'll Find This Port

Port 3629 appears wherever Epson projectors are managed at scale:

• Corporate AV installations with centralized room control
• University lecture halls and auditoriums
• Home theater setups using IP control automation
• OpenHAB, Home Assistant, and other home automation platforms with Epson projector integrations³

It is not a port that should be exposed to the Internet. Epson's control protocol has no authentication layer beyond the session handshake — anyone who can reach port 3629 can control the projector.

Checking What's on This Port

If you see port 3629 active on a device and aren't sure why:

# See what process is listening
sudo lsof -i :3629

# On Linux
sudo ss -tlnp | grep 3629

# Quick banner grab
nc -v <host> 3629

If it's an Epson projector, nc will show the projector's identifier string after a moment. If it's something else, the banner (or silence) will tell you what you're dealing with.

Security Note

Port 3629 should be firewalled from public access. Epson's ESC/VP.net protocol was designed for trusted LAN environments. There is no password. Anyone on the network who can reach this port can power cycle, blank, or reconfigure a projector. In most installations this is fine — projector networks are typically isolated. But if the projector is on a network accessible from outside the building, that's worth fixing.