TURN allocation takes too long sporadically

[ognkrmms]

Hello Paul,

I am using Libdatachannel v0.21.2 with LibJuice v1.4.2 on Windows. I noticed that TURN allocation requests take too long when trying to connect to the Coturn server. I observed that multiple TURN allocation requests are sent without receiving a response, causing the Juice agent to retransmit the request. However, the Coturn server logs show that it receives the request and returns the appropriate response. This problem occurs sporadically, and it happens right after the Windows machine boots up.

Could you please point me in the right direction?

Below, you can find the relevant logs from both the Coturn server and my application.

coturnlogs.txt
applogs.txt

Thanks

[paullouisageneau]

Have you captured network traffic to check whether responses are actually sent by the coturn server?

[ognkrmms]

I have captured network traffic inside Coturn server and I saw that 401 response is sent back to the client for every request. After that, I also tried to capture messages received on the client side and I can confirm that 401-responses are not received for the first 5 attempts. Every time this problem occurs the expected response (401 with nonce) arrives at the last retransmission attempt.

I also have another question. In the detailed example provided in RFC5766 username is not included when the first allocation request. However, libjuice always sends the username. Could this be the root of the problem somehow?

[paullouisageneau]

If the response is sent but dropped somewhere before reaching the client, it looks like a network issue (possibly a firewall blocking the packets) and I'm afraid nothing can be done about it from libjuice side. Is there an observable difference between the first packets and the last one that goes through?

I also have another question. In the detailed example provided in RFC5766 username is not included when the first allocation request. However, libjuice always sends the username. Could this be the root of the problem somehow?

It looks unrelated but the username is indeed useless in the first TURN allocate request. I removed it in #298.

[ognkrmms]

I cannot see any difference between the first packets and the last packet. I think somehow the machine is not ready to receive and I created an external program to send and receive UDP packets at 1 second intervals until it can receive a packet successfully. This way the first response is always received and I lose less time.

Thank you very much for your help.