Transport fails on TCP, only getting connected on UDP

[zaidiqbal]

Hi @Blancduman thanks for this nice work, it is best out there.

Recently have been facing an issue where only TCP ports were open on server and transport was not getting connected instead getting to 'disconnected', 'failed' status. Had to spent quite some time to see what is going on. While checking chrome://webrtc-internals I noticed that the local candidates were not getting generated. Only 'host' candidates were getting generated and 'prflx' candidates, which represents public ip address, were not generating causing transport failure issue.

When I opened the UDP ports on my server as well it started working automatically with same codebase. I guess the candidates are only getting generated on UDP and fails on TCP.

Can you please guide on what can be the issue with TCP connections?. Anything that can be done to resolve that?

thanks