The outer door in Vienna

Experimental setup

1. 01
   Two lines. Normally everything runs over the KabelPlus fibre (1000 Mbit/s down, 100 Mbit/s up). If it fails, the router switches to Starlink by itself and the satellites take over.
2. 02
   The problem. Starlink shares one internet address among many customers. Like a flat without a letterbox of its own: sending post works, but nobody can deliver any to you directly.
3. 03
   The outer door. A small rented server in Vienna whose address never changes. Like a PO box in town: everything that wants to come in from outside arrives there.
4. 04
   The tunnel. From home, an encrypted WireGuard tunnel is built to Vienna and kept open all the time. Because it goes from inside to outside, this works over Starlink too. Through it, the courier brings the post home.
5. 05
   Our own VPN. Phones and laptops on the road also connect to the door in Vienna and end up in the home network through the tunnel, no matter which line the house is using at the moment.

Starlink

Starlink is internet from space: thousands of small satellites circle the Earth at around 550 kilometres, and a flat dish on the roof talks to whichever one is crossing the sky. Because the satellites fly so low, the connection is much faster than old satellite internet. In return, the dish changes partners every few minutes.

There was a measurement experiment of its own for this: a Raspberry Pi at the dish measured the speed every five minutes for 91 days, from December 2023 to March 2024, noted the weather and took a photo of the dish and the sky. The question was: how much does the weather disturb satellite internet?

Average of 91 measuring days, weakest day 181 Mbit/s, best 261 Mbit/s.

Why?

The reason was very practical: urgently needing a document from home while on the road, while nobody at home could fix anything. Since then it does not matter whether the house is online via fibre or via satellite.

For the sender, nothing ever changes. They always knock on the same door.

Test result

Operational. The tunnel is up around the clock, whichever line the house is currently using.

See all measurements Code of the measuring station