Hi, I am facing issue while trying to run “System Compatibility Check” for the CKA exam. While running “https://video-diagnostics.twilio.com/” it suggest “Signaling Gateway unreachable. It’s possible that you’re behind a firewall that will need to be updated by your network administrator.” I am using my personal laptop and have full administrative privileges.
Where are you running your computer? It sounds like there’s something sitting between your computer and the rest of the internet, and that access to that twillio.com site is being blocked. It could be you’re using your laptop on a corporate network; it could even potentially be your ISP. But that’s what the error message means. LF apparently needs access to the site during the exam. If it can’t be accessed during the exam from where you are now, you’ll need to take the exam somewhere else.
Hi Rob, Thanks for reply. I am in Berlin, Germany. I can access twillio.com, and I am using ISP Vodafone and not on any corporate network.
Two possibilities:
- The specific URL
https://video-diagnostics.twilio.com/is unreachable. - The URL has too much latency, and LF’s tester bot is unhappy with that.
I can reach the URL, but then, I’m probably less than 20 or 30 km from where twillio is right now. If you still can’t get it to work, you might want to put in a support ticket with the Linux Foundation and ask about this. If I’ve heard of Vodaphone, and I’m more than 20 or 30 km from Germany, I’d suspect they have as well 
Hi Rob, https://video-diagnostics.twilio.com/ is reachable to me and I am pass audio/video and browser test but connection failed suggestion Signaling Gateway is unreachable.
You’ll need to take it up with support at LF. My sympathy – I’ve not had the best experience with their platform, and if it’s potentially LF’s fault, well, I BLAME LF But create a ticket – they should be able to troubleshoot this for you.