What is port 1900?
Port 1900 is a registered port used by SSDP / UPnP over UDP. Device discovery used by UPnP. A port is like an apartment number at an IP address: it tells incoming traffic which service on the device it belongs to. See the full common ports reference for how this fits with other services.
How to forward port 1900
- Give the device running SSDP / UPnP a fixed local IP (a static IP or a DHCP reservation) so its address never changes.
- Open your router's admin page and find Port Forwarding.
- Create a rule forwarding UDP port 1900 to that device's local IP.
- Save, then test from outside your network.
Walk through it in full with how to set up port forwarding, and plan a stable address with the DHCP pool planner.
Is opening port 1900 safe?
Forwarding any port exposes a service to the internet, so only open port 1900 if you need it, point it at a single device, and keep that device updated. Read is port forwarding safe? before you open anything.