FOTA with OTBR and UDP

RE: FOTA with OTBR and UDP

Menon — Wed, 27 Aug 2025 12:36:02 GMT

Hello,

Sorry for getting back to you a bit late. I was not sure about the issue, so I checked internally with some of my colleagues.

Based on that, the "IPv6 UDP MCUmgr thread is already running" error could indicate that CONFIG_MCUMGR_TRANSPORT_UDP_AUTOMATIC_INIT is set. It is enabled by default, so could you try disabling this config in the application and see if that makes any difference? Also, please check the generated .config file to verify whether this config is being enabled or not.

Kind regards,
Abhij

RE: FOTA with OTBR and UDP

Allan-led — Wed, 13 Aug 2025 17:34:17 GMT

Hi,

There doesn't need to be stress about setting the UDP port with the configuration, as I have verified that this does exist. What is actually confusing are the configurations in the zephyr repository. These are actually the configurations that are no longer supported and not recognized as symbols in the current version of the sdk. I would appreciate any ideas on why this is.

Best regards,

Allan

RE: FOTA with OTBR and UDP

Menon — Wed, 13 Aug 2025 16:07:26 GMT

Hello,

You can find the same in the Zephyr repository and check the branch you wish to review. I looked into the prj.conf file you have shared, and I believe you have enabled all the necessary configurations. However, the setting CONFIG_MCUMGR_TRANSPORT_UDP_PORT is a bit confusing, as I don’t see any such configuration option for setting the port.

Kind regards,

Abhijith

RE: FOTA with OTBR and UDP

Allan-led — Wed, 13 Aug 2025 01:40:15 GMT

Hello,

Could you enlighten me on the previous versions of sample code for MCUMGR and UDP?

I am pretty sure there is one here, but I believe it is taken down. There is also a discussion on this sample here.

I have tried using serial connection to upload images and list images, all of which are successful. However, the UDP is still stuck at NMP timeout.

Best regards,

Allan

RE: FOTA with OTBR and UDP

Allan-led — Thu, 31 Jul 2025 02:25:56 GMT

Hi,

Just another update, I tried sending more packets over to my device. All of them have timed out. But I also verified that connection to the device should okay, as shown below:

_@raspi5-2:~ $ mcumgr --conntype udp --connstring [fdb4:4ee4:da2a:6d93:0:ff:fe00:3000]
:1337 echo hello
Error: NMP timeout
_@raspi5-2:~ $ mcumgr --conntype udp --connstring [fdb4:4ee4:da2a:6d93:0:ff:fe00:3000]:1337 image list
Error: NMP timeout
_@raspi5-2:~ $ nc -6 -u -v fdb4:4ee4:da2a:6d93:0:ff:fe00:3000 1337
Connection to fdb4:4ee4:da2a:6d93:0:ff:fe00:3000 1337 port [udp/*] succeeded!

The dump here also suggests that the packets were indeed delivered, but there has been no response:

I read in another thread that we might need to enable certain configurations to ensure the handlers are enabled, such that my device will respond. I believe I have all the necessary configurations, here is my prj.conf file again, for reference:

#
# Copyright (c) 2020 Nordic Semiconductor
#
# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
#

# Network shell comment out to remove CLI functionality 
CONFIG_SHELL=y
CONFIG_OPENTHREAD_SHELL=y
CONFIG_SHELL_ARGC_MAX=26
CONFIG_SHELL_CMD_BUFF_SIZE=416

# Enable OpenThread features set
CONFIG_OPENTHREAD_NORDIC_LIBRARY_MASTER=y

CONFIG_NET_L2_OPENTHREAD=y
CONFIG_NETWORKING=y

#THREAD CONFIGS
CONFIG_OPENTHREAD=y
CONFIG_OPENTHREAD_SRP_CLIENT=y
CONFIG_OPENTHREAD_FTD=y
CONFIG_OPENTHREAD_JOINER=y
CONFIG_OPENTHREAD_COMMISSIONER=y

CONFIG_SERIAL=n

#RTT CONFIG (Comment out if uart is on)
CONFIG_LOG=y
CONFIG_USE_SEGGER_RTT=y
CONFIG_RTT_CONSOLE=y
CONFIG_SHELL_BACKEND_RTT=y
CONFIG_UART_CONSOLE=n
CONFIG_SHELL_BACKEND_SERIAL=n

#UART CONFIGS FOR RECEIVING COMMANDS (Comment out if rtt is on)
# CONFIG_LOG=y
# CONFIG_SERIAL=y
# CONFIG_UART_CONSOLE=y
# CONFIG_SHELL_BACKEND_SERIAL=y
# CONFIG_USE_SEGGER_RTT=n
# CONFIG_RTT_CONSOLE=n
# CONFIG_SHELL_BACKEND_RTT=n

CONFIG_OPENTHREAD_OPERATIONAL_DATASET_AUTO_INIT=n
CONFIG_OPENTHREAD_DEBUG=y
CONFIG_OPENTHREAD_LOG_LEVEL_DEBG=y

# Storage
CONFIG_SETTINGS_ZMS=y
CONFIG_ZMS=y
CONFIG_NVS=n
CONFIG_SPI_NOR=n
CONFIG_PWM=y

CONFIG_MAIN_STACK_SIZE=6144
CONFIG_SHELL_STACK_SIZE=2048
CONFIG_MCUMGR_TRANSPORT_UDP_STACK_SIZE=2048

CONFIG_BOOTLOADER_MCUBOOT=y      # Enables image format compatibility

CONFIG_MCUMGR_TRANSPORT_UDP=y
CONFIG_MCUMGR_TRANSPORT_UDP_IPV6=y
CONFIG_NET_UDP=y
CONFIG_NET_IPV6=y
CONFIG_NET_SOCKETS_SOCKOPT_TLS=y
CONFIG_MCUMGR_TRANSPORT_UDP_PORT=1337

CONFIG_NET_BUF=y
CONFIG_ZCBOR=y
CONFIG_CRC=y
CONFIG_MCUMGR=y

CONFIG_NET_SOCKETS=y
CONFIG_STATS=y
CONFIG_IMG_MANAGER=y
CONFIG_MCUMGR_SMP_COMMAND_STATUS_HOOKS=y
CONFIG_MCUMGR_GRP_IMG=y
CONFIG_MCUMGR_GRP_OS=y
CONFIG_MCUMGR_GRP_STAT=y
CONFIG_STREAM_FLASH=y
CONFIG_MCUBOOT_IMG_MANAGER=y

CONFIG_MCUMGR_MGMT_NOTIFICATION_HOOKS=y
CONFIG_MCUMGR_GRP_IMG_STATUS_HOOKS=y
CONFIG_MCUMGR_GRP_IMG_IMAGE_SLOT_STATE_HOOK=y
CONFIG_MCUMGR_GRP_IMG_IMAGE_SLOT_STATE_STATES=20
CONFIG_MCUMGR_LOG_LEVEL_DBG=y

CONFIG_THREAD_MONITOR=y
CONFIG_MCUMGR_GRP_OS_TASKSTAT=y
CONFIG_MCUMGR_TRANSPORT_NETBUF_SIZE=1024
CONFIG_NET_BUF_DATA_SIZE=128
CONFIG_MCUMGR_GRP_OS_MCUMGR_PARAMS=y
CONFIG_MCUMGR_TRANSPORT_WORKQUEUE_STACK_SIZE=4608

CONFIG_FLASH=y
CONFIG_FLASH_MAP=y

Best regards,

Allan

RE: FOTA with OTBR and UDP

Allan-led — Wed, 30 Jul 2025 18:58:19 GMT

Hi,

Totally understandable, I was also on a break yesterday so I was unable to get back to you.

Here is a relevant chunk of code and log from my nRF54l15 development board. I call smp_udp_open from the state changed callback function; when my device attaches to the network as a child, it will call smp_udp_open.

However, I am unsure of what exactly is producing the error. If the function did not return successfully, then according to my code it should log "Error initializing SMP UDP transport with smp_udp_open()"? However, this log is not present, this may be an indication that smp_udp_open probably returned successfully. We are however, seeing another error that was not manually written by me, I am suspecting that one of the configurations in prj.conf lead to this. The full list of my configurations are attached below for your reference. Thanks!

#
# Copyright (c) 2020 Nordic Semiconductor
#
# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
#

CONFIG_APP_LIGHTS=y
# Network shell comment out to remove CLI functionality 
CONFIG_SHELL=y
CONFIG_OPENTHREAD_SHELL=y
CONFIG_SHELL_ARGC_MAX=26
CONFIG_SHELL_CMD_BUFF_SIZE=416

# Enable OpenThread features set
CONFIG_OPENTHREAD_NORDIC_LIBRARY_MASTER=y

CONFIG_NET_L2_OPENTHREAD=y
CONFIG_NETWORKING=y

#THREAD CONFIGS
CONFIG_OPENTHREAD=y
CONFIG_OPENTHREAD_SRP_CLIENT=y
CONFIG_OPENTHREAD_FTD=y
CONFIG_OPENTHREAD_JOINER=y
CONFIG_OPENTHREAD_COMMISSIONER=y

CONFIG_SERIAL=n

#RTT CONFIG (Comment out if uart is on)
CONFIG_LOG=y
CONFIG_USE_SEGGER_RTT=y
CONFIG_RTT_CONSOLE=y
CONFIG_SHELL_BACKEND_RTT=y
CONFIG_UART_CONSOLE=n
CONFIG_SHELL_BACKEND_SERIAL=n

#UART CONFIGS FOR RECEIVING COMMANDS (Comment out if rtt is on)
# CONFIG_LOG=y
# CONFIG_SERIAL=y
# CONFIG_UART_CONSOLE=y
# CONFIG_SHELL_BACKEND_SERIAL=y
# CONFIG_USE_SEGGER_RTT=n
# CONFIG_RTT_CONSOLE=n
# CONFIG_SHELL_BACKEND_RTT=n

CONFIG_OPENTHREAD_OPERATIONAL_DATASET_AUTO_INIT=n
CONFIG_OPENTHREAD_DEBUG=y
CONFIG_OPENTHREAD_LOG_LEVEL_DEBG=y

# Storage
CONFIG_SETTINGS_ZMS=y
CONFIG_ZMS=y
CONFIG_NVS=n
CONFIG_SPI_NOR=n
CONFIG_PWM=y

CONFIG_MAIN_STACK_SIZE=6144
CONFIG_SHELL_STACK_SIZE=2048
CONFIG_MCUMGR_TRANSPORT_UDP_STACK_SIZE=2048

CONFIG_BOOTLOADER_MCUBOOT=y      # Enables image format compatibility

CONFIG_MCUMGR_TRANSPORT_UDP=y
CONFIG_MCUMGR_TRANSPORT_UDP_IPV6=y
CONFIG_MCUMGR_TRANSPORT_UDP_PORT=8905

CONFIG_NET_BUF=y
CONFIG_ZCBOR=y
CONFIG_CRC=y
CONFIG_MCUMGR=y

CONFIG_NET_SOCKETS=y
CONFIG_STATS=y
CONFIG_IMG_MANAGER=y
CONFIG_MCUMGR_GRP_IMG=y
CONFIG_MCUMGR_GRP_OS=y
CONFIG_MCUMGR_GRP_STAT=y
CONFIG_STREAM_FLASH=y

CONFIG_MCUMGR_MGMT_NOTIFICATION_HOOKS=y
CONFIG_MCUMGR_GRP_IMG_STATUS_HOOKS=y
CONFIG_MCUMGR_GRP_IMG_IMAGE_SLOT_STATE_HOOK=y
CONFIG_MCUMGR_GRP_IMG_IMAGE_SLOT_STATE_STATES=20
CONFIG_THREAD_MONITOR=y
CONFIG_MCUMGR_GRP_OS_TASKSTAT=y
CONFIG_MCUMGR_TRANSPORT_NETBUF_SIZE=2475
CONFIG_MCUMGR_GRP_OS_MCUMGR_PARAMS=y
CONFIG_MCUMGR_TRANSPORT_WORKQUEUE_STACK_SIZE=4608

CONFIG_FLASH=y
CONFIG_FLASH_MAP=y

Best regards,

Allan

RE: FOTA with OTBR and UDP

Menon — Mon, 28 Jul 2025 12:55:13 GMT

Hello,

Sorry for getting back to you late. It's summer vacation here in Norway, and many are on vacation, which has created some delay in getting back to this.

[quote user="Allan-led"], could you please clarify what you mean by the nRF side? [/quote]

Coming back to the issue:

By nRF side, I mean the logs from the nRF54L15 to see whether it is responding to the mcumgr commands. How do you open the socket? Are you using smp_udp_open()? Can you add a log after calling smp_udp_open()?

I am not sure if using the Kconfig option MCUMGR_TRANSPORT_UDP_PORT can be used to configure the port number. In this example, it is done at runtime not via Kconfig, and the application has been built with the appropriate UDP transport like CONFIG_MCUMGR_TRANSPORT_UDP_IPV4 or CONFIG_MCUMGR_TRANSPORT_UDP_IPV6.

Kind Regards,

Abhijith

RE: FOTA with OTBR and UDP

Allan-led — Wed, 23 Jul 2025 23:35:10 GMT

Hello is anyone still able to assist with this?

RE: FOTA with OTBR and UDP

Allan-led — Wed, 16 Jul 2025 17:25:02 GMT

Hi,

Sorry, could you please clarify what you mean by the nRF side?

I have always been looking at the debug logs from the RTT. In the example below, I'm sending the image list to port 8341 (instead of the correct MCUMGR_TRANSPORT_UDP_PORT, this is the port where I have a handler that prints the bytes received. I have trouble logging the outputs of another port) :

I believe the above is an indication of the pi and nRF54L15 are connected, and I'm able to catch the bytes sent to me this way, but just at the wrong port.

I have configured CONFIG_MCUMGR_TRANSPORT_UDP_PORT=8905, but when I specify this port while sending the mcumgr command, it also gives NMP timeout and the progress bar is stuck at 0% during the upload. Is there any code that I need to set up manually for this to work out? So far I've only enabled the relevant configurations and haven't written extra code related to FOTA.

Best regards,

Allan

RE: FOTA with OTBR and UDP

Menon — Wed, 16 Jul 2025 14:18:36 GMT

Hello,

Are you checking the logs from the nRF side? If so, what do they say? Is there any log that confirms the mcumgr command has been received?
I wanted to know which side is failing, the Pi or the nRF54.

Kind regards,
Abhijith

RE: FOTA with OTBR and UDP

Allan-led — Tue, 15 Jul 2025 01:38:00 GMT

Hi,

Increasing the buffer size did allow me to capture all of the bytes sent to me (I tried logging the bytes from a custom port, not 1337). However, it appears to me that I have not started the process correctly. I configured the SMP TRANSPORT UDP, and from the logs alone, I think it is starting correctly (the smp_udp module logged success):

I also tried executing ping6 <ipv6> on the pi:

279 packets transmitted, 233 received, 16.4875% packet loss, time 279378ms
rtt min/avg/max/mdev = 12.510/16.910/28.840/3.133 ms

The statistics above suggest that my device is indeed reachable, with occasional packet loss.

However, executing mcumgr commands result in a timeout. It never responds, and even if we try sending the packages, the process bar still gets stuck at 0%.

mcumgr --conntype udp --connstring [fdb4:4ee4:da2a:6d93:0:ff:fe00:b400]:1337 image list
Error: NMP timeout

mcumgr --conntype udp --connstring [fdb4:4ee4:da2a:6d93:0:ff:fe00:b400]:1337 im
age upload dfu/ot-light-base.signed.bin
0 B / 492.27 KiB [-------------------------------------------------------------------------] 0.00%

I'd appreciate any help, thanks!

Best regards,

Allan

RE: FOTA with OTBR and UDP

Allan-led — Mon, 14 Jul 2025 17:24:32 GMT

Hi,

I will try increasing the buffer size and let you know how it goes as soon as possible. However, we must use the approach with OTBR and UDP.

I am using v3.0.1 of the nRF Connect SDK.

Best regards,

Allan Wang

RE: FOTA with OTBR and UDP

Menon — Mon, 14 Jul 2025 11:01:56 GMT

Hello,

If you check the SMP specification, a 64-byte buffer might work for SMP over UART, since it deals with small, framed, base64-encoded packets with a size limit of around 127 bytes.

But for SMP over UDP, this buffer size is likely too small. I suggest starting with a 512-byte buffer, and increasing it to 1024 bytes if you encounter issues like stalled uploads or dropped packets.

Which SDK version is this, because the link you shared points to an old SDK version?

Kind Regards,

Abhijith

RE: FOTA with OTBR and UDP

Allan-led — Fri, 11 Jul 2025 23:19:10 GMT

As an update, I have resolved the problems described above. I am able to initiate the image upload at this point, it gets captured, but blocked off by my udp callback handler. This is because the udp callback handler only allocates a buffer of size 64 bytes, which was mainly for previous design. How much should I increase it to this time? I don't really want to deal with a huge buffer for every udp message that I receive...