TCP connection cannot be established for a long time (about 4.5 hours) through BLE IPv6

RE: TCP connection cannot be established for a long time (about 4.5 hours) through BLE IPv6

Einar Thorsrud — Wed, 15 Jan 2020 19:20:20 GMT

I see. I do not have a good idea to be honest, but I will try to look into it and get back to you.

RE: TCP connection cannot be established for a long time (about 4.5 hours) through BLE IPv6

michael lee — Tue, 14 Jan 2020 06:58:26 GMT

There are some the RPi logs as follows.

The BLE CC OK means BLE PHY connected and IPv6 interface established. The NW CC NG means TCP connection is failed. The BT interface status is printed during The NW CC NG. One more retry after NW CC NG. Unfortunately, we don't see any effective information from the above logs.

RE: TCP connection cannot be established for a long time (about 4.5 hours) through BLE IPv6

Einar Thorsrud — Thu, 02 Jan 2020 08:45:20 GMT

Hi,

It looks to me like the nRF is connectable, but the RPi does not connect for some reason. What is the state of the RPi? Do you have logs from there? Since this is where the problem is, I suspect here is where you need to look.

RE: TCP connection cannot be established for a long time (about 4.5 hours) through BLE IPv6

michael lee — Sun, 22 Dec 2019 09:20:37 GMT

Hi，

OK, I've learned that the response time will be longer during Christmas. I hope there will be some progress after the holiday in January.

RE: TCP connection cannot be established for a long time (about 4.5 hours) through BLE IPv6

Einar Thorsrud — Fri, 20 Dec 2019 14:15:46 GMT

Hi,

OK. I am a bit puzzled since this comment made me think the nRF may be in a bad state:

"Further more, the log is printed at the every abnormal returns of the NS message receiving path. It is found that no log is printed during the connection cannot be established. It can be inferred that the SoftDevice does not return any message to the application layer during the connection cannot be established."

But this is actually on the gateway?

Please note that there will be an increase in response time from Nordic employes during the Christmas holiday (starting now), but I will be back in the beginning of January.

RE: TCP connection cannot be established for a long time (about 4.5 hours) through BLE IPv6

michael lee — Fri, 20 Dec 2019 02:48:25 GMT

Hi，Thank you for your reply.

Here have some nRF logs of TCP connection but I don't know if it helps.

First it is normal logs of our TCP connect and disconnect, we can see the ICMP6 NS event clearly.

Next is the failed logs, we can see that the ICMP6 NS has not been received. The connection timed out 40 seconds after the IPv6 interface was established, and then the BLE connection was disconnected. The process lasted about 4.5 hours.

Finally, the fault is automatically recovered, and the TCP connection can be completed normally again.

In addition, if the log output of BLE IPSP/BLE 6lowpan/lwIP stack driver is enabled, the fault may not be repeated.

RE: TCP connection cannot be established for a long time (about 4.5 hours) through BLE IPv6

Einar Thorsrud — Thu, 19 Dec 2019 14:13:11 GMT

Hi,

Since no logs are written etc. I assume the expected code is not executing. Could it be that the application is stuck waiting for something that does not happen? Either some very long app_timer timeout, or could it be that the application enters a bad state, and stays that way until something triggers a reset? This is just vague ideas. I suggest you try to debug on the nRF side to see what is actually going on there.