Thingy91 lwm2m FOTA update

RE: Thingy91 lwm2m FOTA update

Hakon — Thu, 01 Feb 2024 12:20:05 GMT

Can you enable Wireshark captures? If the download works on thingy91 but not on custom board, then it could be that the custom board does not have the same SEC_TAG content provisioned.

RE: Thingy91 lwm2m FOTA update

Hkhan7861 — Thu, 16 Nov 2023 11:08:54 GMT

Good afternoon

We were able to get FOTA working solidly with th3 thingy91. However, when we run our custom board we are running into more issues. The client we have uses the lwm2m_send functions to send data to our server.

In order to do this, we have to add this to our prj file:

CONFIG_JSON_LIBRARY=y
CONFIG_BASE64=y
CONFIG_LWM2M_RW_SENML_JSON_SUPPORT=y

when we write the url we get this error :

[00:00:03.761,688] <err> fota_download_util: Unsupported Image type 0

We have attributed this to our

dfu_target_type enum equalling 0. Which means that the image type is 'none'. Is there a reason why it is not supported and is there any easy configuration i can do instead of changing the SDK?

Thank you in advance

Hassan

RE: Thingy91 lwm2m FOTA update

Hkhan7861 — Thu, 16 Nov 2023 07:54:46 GMT

Hi Hakon

When i set the sec_tag manually for both downloader and client it seemed to have work. Thank you !

RE: Thingy91 lwm2m FOTA update

Hkhan7861 — Thu, 16 Nov 2023 06:17:36 GMT

Hi Hakon

Im trying to confirm that but i don't know which sec tag is written for our server. Im assuming its the same as the Leshan server uses but i can't confirm. Can you assist me in finding out which sec tag to use?

Thank you in advance.

Kind regards,

Hassan

RE: Thingy91 lwm2m FOTA update

Hakon — Wed, 15 Nov 2023 14:41:25 GMT

Have you checked that download client is using the sec tag where the PSK is written?

RE: Thingy91 lwm2m FOTA update

Hkhan7861 — Wed, 15 Nov 2023 12:12:15 GMT

Hi Hakon

I have downloaded SDK2.5. Our files are downloaded on the lwm2m server that we have been communicating with. When I insert the coap URL in the lwmm2m object, i get this error every time:

[00:00:19.289,245] <inf> app_lwm2m_client: FOTA download started for instance 0
[00:00:19.292,999] <inf> fota_download_util: Download url coaps://REDACTED/files/lwm2m-demo-2_1.0_1.0.hex
[00:00:19.293,090] <inf> fota_download_util: Download Path files/lwm2m-demo-2_1.0_1.0.hex host coaps://dev.lwm2m.automatechcloud.co.za:5684
[00:00:19.294,708] <inf> download_client: Downloading: files/lwm2m-demo-2_1.0_1.0.hex [0]
[00:00:29.620,208] <inf> download_client: Setting up TLS credentials, sec tag count 1
[00:00:29.620,697] <inf> download_client: Connecting to coaps://dev.lwm2m.automatechcloud.co.za:5684
[00:00:30.355,987] <err> download_client: Unable to connect, errno 111
[00:00:30.356,018] <err> fota_download: Download client error
[00:00:30.356,903] <err> lwm2m_firmware: FOTA_DOWNLOAD_EVT_ERROR
[00:00:30.356,933] <inf> lwm2m_firmware: FOTA download failed, target 0
[00:00:30.364,959] <err> fota_download_util: Unsupported Image type 0
[00:00:30.364,990] <err> lwm2m_firmware: Failed to reset DFU target, err: -13
[00:00:30.369,384] <inf> app_lwm2m_client: FOTA failure 0 by status 4
[00:00:49.294,708] <dbg> app_lwm2m_client: rd_client_event: Queue mode RX window closed

It seems as though the client attempts to use SEC_TAGs when trying to connect to the server. FIrstly, the client is already connected and secondly it should be trying to connect with PSK. What would i need to change to make this possible.

Thank you,

Kind regards,

Hassan

RE: Thingy91 lwm2m FOTA update

Achim Kraus — Wed, 25 Oct 2023 08:41:54 GMT

> pull over our dedicated coAP server

If that supports CoAP/DTLS 1.2. As I wrote above, if the download is executed "in time", means without breaks/pauses, CID maybe used, but is not a game-changer. CID is very helpful, if your traffic uses larger pauses in order to save energy. But if you "connect to download the firmware without pauses", then it's not really required. What will be required is CoAP blockwise (RFC 7959) on both sides, client and server.

RE: Thingy91 lwm2m FOTA update

Hkhan7861 — Wed, 25 Oct 2023 07:00:22 GMT

Hi Achim

Thank you so much for this explanation. So in other words, all i would really need to do is use SDK 2.5.0, enable CID support and then pull over our dedicated coAP server?

Kind regards,

Hassan

RE: Thingy91 lwm2m FOTA update

Achim Kraus — Wed, 25 Oct 2023 06:54:33 GMT

http and https are based on TCP and TLS.

DTLS is based on UDP.

So, using DTLS 1.2 CID doesn't change the usage of TCP/TLS at all. So it will not make the updates over http possible.

The pain with TCP/TLS is mainly, that these protocols assumes some "timings", which then are not always fulfilled using NB-IoT. There is some overlap (therefore it works sometimes), but there is also a large region, where the times doesn't fit (therefore too often it doesn't work).

Using CoAP/DTLS 1.2 CID these times are relaxed and fits NB-IoT.

RE: Thingy91 lwm2m FOTA update

Hkhan7861 — Wed, 25 Oct 2023 06:33:06 GMT

Hi Hakon

Would this make it possible to pull updates over http and https?

The process fails immediately when attempted now over nbiot.

kind regards,

Hassan

RE: Thingy91 lwm2m FOTA update

Sigurd — Thu, 19 Oct 2023 08:42:37 GMT

Hi! It will be part of nRF Connect SDK v2.5.0. PR with this feature can be found here: https://github.com/nrfconnect/sdk-nrf/pull/12412

RE: Thingy91 lwm2m FOTA update

Achim Kraus — Mon, 16 Oct 2023 18:37:40 GMT

You're welcome.

RE: Thingy91 lwm2m FOTA update

Hkhan7861 — Mon, 16 Oct 2023 08:27:57 GMT

Hi Achim

Thank you so much for this!

Kind regards,

Hassan

RE: Thingy91 lwm2m FOTA update

Hkhan7861 — Mon, 16 Oct 2023 08:27:25 GMT

Hi Hakon

Thank you for the update that is amazing news ! Please update this ticket as soon as its available.

Kind regards,

Hassan

RE: Thingy91 lwm2m FOTA update

Achim Kraus — Sun, 08 Oct 2023 09:03:30 GMT

Enable connection ID support for coap is pretty simple, see simple coap sample to send data to the nrf cloud .

The interesting point would be, why connection ID is considered for FOTA. Except, that you have longer quiet phases, I'm not sure to see the advantage of CID in an case, where messages are exchanged every 2-4s.

RE: Thingy91 lwm2m FOTA update

Hakon — Mon, 02 Oct 2023 07:58:51 GMT

Modem team;

We are developing DTLS Connection ID support in Download client. That should help in slow Nb-IOT networks if certificates are used.

However, the recommendation on such slow networks is not to use X509 certificates in DTLS handshake.

RE: Thingy91 lwm2m FOTA update

Hakon — Mon, 24 Jul 2023 13:07:10 GMT

I didn't find much, perhaps this can be useful https://dzone.com/articles/coap-protocol-step-by-step-guide.

RE: Thingy91 lwm2m FOTA update

Hkhan7861 — Wed, 19 Jul 2023 06:56:21 GMT

Would also like to ask whether I could find a guide on implementing coaps(enabling a connection ID) with the download client as I have very little knowledge about this at the moment.

RE: Thingy91 lwm2m FOTA update

Hkhan7861 — Wed, 19 Jul 2023 06:31:48 GMT

Hi Hakon

Thank you for the reply. Sorry about not replying earlier but i'm ready to tackle this issue again. Thank you for again for the advice I will try what you have suggested.

Kind regards,

Hassan

RE: Thingy91 lwm2m FOTA update

Hakon — Fri, 23 Jun 2023 12:08:23 GMT

The modem team has commented;

I believe I can now replicate this.

Test environment

I’m using modem FW 1.3.5 release candidate. nRF Connect SDK main(v2.4.0-94-gdfb7d043b).

As a test application, I’m using HTTP download sample with Download client shell and AT shell enabled.

I configured LTE Link manager to connect to Nb-IOT instead of LTE-M. This is verified by AT%XSYSTEMMODE? command above.

My conclusion is that Nb-IoT is too slow to be used with normally configured HTTPS servers. We end up getting timeout before the TLS stack can finnish the TLS handshake and continue with HTTP.

I would suggest to use CoAP or CoAPS (DTLS) when downloading with Nb-IoT. When DTLS is used, prefer PSK or very small ECC certificates with short chain length.

I don’t believe this issue can be fixed in SDK software.

I was testing this further with COAPS.

And even there, I see problems with timeouts. Looks like a handshake with server that uses certificates, takes so long that NAT timeout might happen, so all the following CoAP GET queries are lost.

When DTLS Connection ID is used, the downloads starts to work on almost 100% success rate.

Enabling Connection ID with download client would require code change.

RE: Thingy91 lwm2m FOTA update

Hkhan7861 — Thu, 01 Jun 2023 11:56:34 GMT

Hi Hakon

Thanks for the update. I haven't changed any configuration regarding that. This is happening every time. Have they tested the update using NBIOT?

Kind regards,

Hassan

RE: Thingy91 lwm2m FOTA update

Hakon — Thu, 01 Jun 2023 11:49:48 GMT

Modem team has responded now;

I can only replicate this behavior when I try to connect to a server that does not listen for incoming connections on that port.

uart:~$ lwm2m update
[00:04:34.702,362] <inf> net_lwm2m_engine: Connected, sock id 0
[00:04:34.888,397] <inf> net_lwm2m_rd_client: Update callback (code:2.4)
[00:04:34.888,427] <dbg> app_lwm2m_client: rd_client_event: Registration update complete
[00:04:34.888,458] <inf> net_lwm2m_rd_client: Update Done
[00:04:34.940,155] <inf> download_client: Setting up TLS credentials, tag 16842753
[00:04:34.940,246] <inf> download_client: Connecting to https://example.com:8000

[00:04:58.942,626] <err> download_client: Unable to connect, errno 116
[00:04:58.943,023] <err> lwm2m_firmware: fota_download_start() failed, return code -116
[00:04:58.944,305] <wrn> fota_download: fota_download_cancel invalid state
[00:04:58.944,335] <err> lwm2m_firmware: Unsupported Image type 0
[00:04:58.944,366] <err> lwm2m_firmware: Failed to reset DFU target, err: -13
[00:05:05.216,278] <dbg> app_lwm2m_client: rd_client_event: Queue mode RX window closed

Is this error happening every time with them?

Also, the timeout seem to happen quite quickly (200 ms). Have they changed some configuration regarding that?

RE: Thingy91 lwm2m FOTA update

Hkhan7861 — Wed, 24 May 2023 11:28:40 GMT

Good day

Any news on this ?

RE: Thingy91 lwm2m FOTA update

Hakon — Tue, 09 May 2023 12:52:23 GMT

Thanks, I have reported this internally now.

RE: Thingy91 lwm2m FOTA update

Hkhan7861 — Tue, 02 May 2023 07:13:07 GMT

Good day

I am using mfw_nrf9160_1.3.4.