If you have a user running qualityRTC complaining that his sessions sometimes connect and sometimes doesn’t, and you get similar types of results in the TURN CONNECTIVITY tests of qualityRTC, then this might be due to a firewall configuration on the user’s side.
Here’s how a successful result might look like, along with the relevant log message for the TLS connection:
Here’s how a failed result might look like, along with the relevant log message for the TLS connection:
Why is that happening?
WebRTC is quite dynamic in nature. It uses multiple server types, multiple IP addresses, multiple ports and even runs over UDP, TCP and TLS – as needed.
This means that sometimes, sessions might get connected properly, while other times they might not.
In the example above, the TURN servers used are being allocated by the infrastructure vendor provide different TURN/TLS servers in each call. This means that each time, a different IP address is being connected to for the session.
Since sometimes it fails and sometimes it succeeds, it brings into suspicion the potential use of a firewall on the client side that is not configured properly.
What can you do?
The user conducting the tests should check if he has a firewall configured and turn it off (or fix its configuration).