CoAP Client/Server not attaching

RE: CoAP Client/Server not attaching

Jørgen Holmefjord — Wed, 05 Oct 2022 10:49:14 GMT

Yes, that should give more details.

You may also set CONFIG_OPENTHREAD_L2_LOG_LEVEL_DBG and CONFIG_OPENTHREAD_L2_DEBUG if the above configs does not help indicating what is happening.

RE: CoAP Client/Server not attaching

kaushalyasat — Tue, 04 Oct 2022 02:00:45 GMT

Hi Jørgen,

Yes I think it happens while runtime. Probably when I was testing range, I was taking the client further away until it no longer make connection. Then I saw this behavior.

I have set the following in my prj.conf for the server.

CONFIG_LOG=y

CONFIG_OPENTHREAD_DEBUG=y

CONFIG_OPENTHREAD_LOG_LEVEL_DEBG=y

Is this enough?

Cheers,

Kaushalya

RE: CoAP Client/Server not attaching

Jørgen Holmefjord — Fri, 30 Sep 2022 12:22:08 GMT

[quote user="kaushalyasat"]When I ilook into CoAP server mode, it was in Full Network Data. (ot mode replies 'n')[/quote]

Does this change during run-time? If it does, can you check if the log gives any details on why this happens? You might need to increase the log level to get more details.

RE: CoAP Client/Server not attaching

kaushalyasat — Fri, 30 Sep 2022 10:21:18 GMT

I think I have found may be why this happens. When I ilook into CoAP server mode, it was in Full Network Data. (ot mode replies 'n')

Then I changed mode to rdn (ot mode rdn) and then it came back to leader role.

Once I do that then it kept on in this mode even after power cycle.

So may be due to whatever reason, the CoAP server changes its mode to 'Full Network Data' and losses 'rx-on-when-idle' and 'Full Thread Device'.

Any idea what could trigger this behavior?

If I again set mode to 'n', same this happens and it persists even after power cycle.

I will try to set this mode in thread init function and see.

RE: CoAP Client/Server not attaching

kaushalyasat — Fri, 30 Sep 2022 00:29:23 GMT

Hi Jørgen,

Now I have been testing my modified server/client projects successfully until this morning and again the system went back to that phantom state of server/client failing to attach.

I am desperate for a solution now.

Thanks

RE: CoAP Client/Server not attaching

kaushalyasat — Thu, 29 Sep 2022 03:14:06 GMT

Thanks Jørgen.

Apologies for my delay, I had to sort out a production issue.

The code I am trying now is straight out of the example code. So no modifications.

There were no other OpenThread devices in the vicinity. So I am not sure how these fe80::cc96:a5e5:3ec1:4aec and fe80::f0dd:73af:496a:9446 became children. We only have number of Thread devices in the lab. Can they be attaching to OpenThread networks?

To become a child, it should have the same PANID, network name and network key as the server, am I correct?

To make it even worse(??) the server is now becoming a Leader. I didnt do anything. I can see LED1 on server lighting up.

Really need some help here.

This is the network session from wireshark. devzone.nordicsemi.com/.../CoAP-session_2D00_Working.pcapng

Thanks,

RE: CoAP Client/Server not attaching

Jørgen Holmefjord — Tue, 27 Sep 2022 14:53:44 GMT

Hi,

How have you modified the samples? Could you provide the code/projects?

Looking at you sniffer log, it seems that initially there is a router\parent present (fe80::4cc8:a3aa:4415:e77e) with two children attached (fe80::cc96:a5e5:3ec1:4aec and fe80::f0dd:73af:496a:9446).

In the end of the sniffer trace, it seems these two children are looking for a parent, but the previous parent is no longer sending packets. However, there seems to be another device present in the sniffer log (fe80::7c02:908c:d37b:8a79), but this is configured at another PANID (0xFFFF, not 0xABCD like the other nodes), so this may be interference from another network.

Best regards,
Jørgen

RE: CoAP Client/Server not attaching

kaushalyasat — Tue, 27 Sep 2022 04:14:18 GMT

The wireshark session is attached.

devzone.nordicsemi.com/.../CoAP-session_2D00_Fail.pcapng

RE: CoAP Client/Server not attaching

kaushalyasat — Tue, 27 Sep 2022 01:47:47 GMT

I have added

CONFIG_NET_IPV6=y

CONFIG_NET_UDP=y

to prj.conf of both coap_client and coap_server projects, but same result.