Shutdown of the Matrix VoIP Tester

2024-05-08

Dear visitor,

I'm afraid to say that I have decided to shut down the Matrix VoIP Tester.

Inspired by the federation tester, I developed the VoIP Tester in the summers of 2019 and 2020 as part of internships at Element (which was called Riot.im back then :-)). After going through the joy of running my own homeserver and the pain of running a working TURN setup for it, I wanted to make this easier for other people (and myself!). So I asked the powers that be to let me write such a tester towards the end of the internship and happily they agreed :D.

I certainly learnt a lot about WebRTC along the way. I now know that writing an in-browser VoIP tester is not the best way to go — browsers just don't give you enough control to exercise over all the connection details. And some browsers act differently to others! Worse, they give you virtually no information when nothing goes wrong — usually no specific errors, just a connection failure.

The VoIP tester was originally going to live at Matrix.org like the Federation tester does, but I think there were still a few loose ends at the end of my internship and so I fixed it up afterwards and published it here, test.voip.librepush.net.

At some point in 2021, someone added a link to this service in the Synapse documentation and I guess quite a few people came here that way, but I haven't counted :-).

Since running it on my server in 2020, it's been surprisingly stable. At first I was running it in a screen session — I didn't get around to turning this into a proper systemd unit until May 2021 (real life does get in the way!). Because of this, a couple of times people have (unexpectedly!) poked me to start it up again when it was down, but other than that it's been running ever since without me having to touch it.

But it's fair to say there are a few curses which lead me to decide to shut it down today:

• the tester is not entirely reliable — the results vary by browser and even then it can give you errors even when your setup is correct
• even though my setup passes the tester, I still have issues starting calls. I don't have the time to go spelunking in client code right now to diagnose or fix this myself and I think for the client developers, VoIP is low on the list of priorities right now.
  • though e.g. Element is developing a new style of VoIP called MatrixRTC (with their client called Element Call) that supports multiple users, so they are focussing their attention on that
  • and the Element mobile apps are on a collision course to be replaced with Element X sometime, so understandably there is no real desire to go poking at the old apps' VoIP problems
• making a reliable tester would realistically mean writing a test server to perform the STUN/TURN connections rather than doing it in-browser, but even though I did lightly poke at this, I don't have enough time for this now, all things considered.
• I am changing the way I operate my server and keeping this service online would need me to spend some time to port over, but for the reasons above I don't think this is worth doing.

Thank you for 43 months of using this tool.

If you'd like to run it yourself, despite the caveats, the source code is available at https://github.com/matrix-org/voip-tester (check the PRs as there's still one PR that I couldn't merge into the repository, but do run on my server here).

Cheers,
Olivier 'reivilibre'

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If you need to contact me:

• electronic mail: voip.contact [ alphabetic-ish symbol ] librepush [ full stop ] net
• Matrix: [ user ID sigil ] reivilibre [ colon ] librepush [ full stop ] net