Host a watch party without port forwarding: UPnP, a tunnel, or the same network
The hard part of watching together is not the video, it is the network between your PC and theirs. Timeline gives you three ways across it.
LAAGU··3 min readTimeline
Why a connection method is needed
Your video streams straight from your PC to your guests. That keeps it private and needs no upload, but guests' computers have to be able to reach yours. Most home routers block incoming connections, so the Host dialog asks how guests should reach you.
| Method | Best for | What it needs |
|---|---|---|
| Automatic (UPnP) | Friends on the internet; the easiest if it works | A router with UPnP turned on |
| A tunnel address | When UPnP is off or unavailable | An address from a tunnel service such as playit.gg, ngrok or PortWarp |
| Same network | People in the same house or office | Nothing: guests are on your Wi-Fi or LAN |
Try it in Timeline
Free for Windows 10 and 11. One installer, nothing else to set up.
Automatic: UPnP
With UPnP, Timeline asks your router to open a port for the session, and closes it again when the session ends. The 600-second lease is renewed while you host, and the mapping is removed when you end the session or the app exits.
- In the Host dialog, pick the automatic method.
- Click Check my router. It is a read-only test: Timeline listens for a UPnP answer and changes nothing.
- If the router answers, start the session.
Careful. UPnP only works if your router supports it and has it switched on. If your internet provider shares one public address between many customers (known as CGNAT), automatic mapping cannot work: Timeline detects a private external address, refuses, and tells you to use a tunnel instead.
A tunnel address
A tunnel service gives you a public address that forwards to your PC, with no router settings involved. Timeline supports addresses from playit.gg, ngrok or PortWarp.
- Set up the tunnel service for the port Timeline will use (it is shown in the Host dialog and you can change it).
- Choose the manual option in the Host dialog and paste the public address.
- Click Test connection. Timeline checks the address from outside.
- If it passes, start. If it fails, you can still choose Start anyway.
The test asks the address for a tiny answer, and it sends a header that skips ngrok's browser warning page, so a working ngrok tunnel passes.
Same network
When everyone is on the same Wi-Fi or LAN, pick Same network. It needs no router changes and no tunnel, and the video does not have to cross the internet, so it is the setup least likely to buffer.
Tips
- Use a wired connection for the host if you can: the host's upload speed is what every guest shares.
- Test with one friend before movie night, not five minutes before it starts.
- If a guest buffers, see fixing buffering: Timeline shows network numbers to help.
Note. Whether a method works depends on your router, your provider and the tunnel service, so it cannot be promised for every network. That is why Timeline has the test buttons.
Questions
Do I need to forward ports myself?
Not if UPnP works on your router: Timeline opens and closes the port automatically. If it does not, use a tunnel address or the same network option.
What is CGNAT and why does it matter?
Some internet providers share one public address between many customers, so your router cannot receive incoming connections. Automatic mapping cannot work then; use a tunnel service.
Which tunnel services does Timeline support?
Any address from a tunnel such as playit.gg, ngrok or PortWarp can be pasted into the Host dialog.
Does Check my router change my router?
No. It is a read-only check that only listens for a UPnP answer.