LTE Modem log configuration

[Yann.P]

Hi there,
I need to collect modem logs to investigate LTE-M connectivity issues in specific countries.
I have been using the command AT%XMODEMTRACE=1,2 to activate them and I am using Wireshark to visualize them.

I am limited in the amount of data I am able to collect and I would like to reduce the verbosity of the logs to the following subset : AT, NAS-EPS, LTE RRC, IP (actually I would need to only collect the traces that can be viewed with Wireshark).

The documentation about the AT%XMODEMTRACE command advises to connect with the support team in order to use the <bitmap_id> and <bitmap> fields and there is no documentation about these fields.

Can you advise me what parameters I should use to limit to the logs to the subset mentioned above ?

Thanks a lot,

Yann

[helsing]

Hello Yann, sorry for the delay.

<bitmap_id> and <bitmap> fields

Sorry, there is no documentation available on these. Sometimes, the modem team might ask customers to use a specific bitmap to get some extra traces.

Have you tried set 5, as in  %XMODEMTRACE=1,5 ? This might be closer to what you are looking for. Does it provide you the information you are seeking?

[Yann.P]

Thank you very much for your answer.

As I have no coredump and as I am not using GNSS, %XMODEMTRACE=1,5 and %XMODEMTRACE=1,2 give me the same amount of data which is very large (1.5MB for 5 minutes of operation) but when I export the collected trace to pcapng format using nrfutil trace lte the results is only a few kB.

Could you forward my question to the modem team that can advise on the use of <bitmap_id> and <bitmap> fields to configure which data is collected ? If would be very helpful for me to be able to reduce the amont of collected traces.

Thank you for your help

Yannick

[Yann.P]

Hello Helsing,
Did you get the opportunity to have a feedback from the modem team on how the use of the <bitmap_id> and <bitmap> fields ?
Thanks a lot,
Yannick

[Charlie]

Hi Yannick,

Håkon is out for Easter vacation and I am handling your case now.

I have just forwarded your questions to our modem team and will provide you an update later. There might be some delay due to Easter holiday. 

Could you further explain why you are limited in the amount of data you can collect? Do you use flash as modem trace backend? 

Best regards,

Charlie

[Charlie]

Hi Yann.P,

Could you try the following configurations? It figures out this bit_map configuration is heavily related to our modem source codes. We are not able to provide more details to explain the configuration. Our modem team provides the bit_maps configuration according to your request now. 

AT%XMODEMTRACE=2,,4,"06"

AT%XMODEMTRACE=2,,0,"00000000000000000000f00000000000"

AT%XMODEMTRACE=2,,3,"000000000000000000000000002004000000000000a001000000000000000000000000000000000000"

Please let me know if it works as expected on your setup. Feel free to contact if you need more help.

Best regards,

Charlie

[Yann.P]

Thank you very much Charlie.
I will test that and will keep you updated.

And to answer your first question : yes, we redirect modem trace to an external flash to be able to analyse them at the end of our roaming tests.

Thanks again
Yannick