Legato cellular data connection issue

1

Hello,

We have a customer using FX30 with Mirage Wifi card. They are having issues with cellular data connection.

Hardware: FX30(WP7702)
Firmware: SWI9X06Y_02.16.06.00 7605a6 jenkins 2018/06/20 17:56:12 Daughter card: Talon IoT, Mirage (WiFi and Bluetooth)

They don’t use the wifi, the Talon card is present for future usage. They also have a custom application to create a data connection through the cellular network and reestablish it if we loose the connection.

A standard log would look like this:

Feb 21 14:42:52 fx30 user.info Legato: INFO | Internetor version 2022.6 Feb 21 14:42:52 fx30 user.info Legato: INFO | Sim IMSI: 310280039759008 Feb 21 14:42:52 fx30 user.info Legato: INFO | Found the STD APN for 310280039759008 : broadband, ‘’, ‘’.
Feb 21 14:42:52 fx30 user.info Legato: INFO | Trying to connect…
Feb 21 14:42:57 fx30 user.info Legato: INFO | Session state changed to 2 Feb 21 14:43:05 fx30 user.info Legato: INFO | rmnet_data0 is now connected.

The rmnet_data0 interface being the data cellular one.

In production, they are seeing following:

Feb 21 07:41:10 fx30 user.info Legato: INFO | Sim IMSI: 310280039759008 Feb 21 07:41:10 fx30 user.info Legato: INFO | Found the STD APN for 310280039759008 : broadband, ‘’, ‘’.
Feb 21 07:41:10 fx30 user.info Legato: INFO | Trying to connect…
Feb 21 07:41:12 fx30 user.info Legato: INFO | Net registration state: 1 Feb 21 07:41:12 fx30 user.info Legato: INFO | Session state changed to 2 Feb 21 07:41:20 fx30 user.info Legato: INFO | wlan0 is now connected.

With wlan0 being usually used for the wifi network.

The interface (dis)connection log is generated in the handler registered with le_data_AddConnectionStateHandler().

Since the FX30 system logs are stored in memory only, they fetch them from time to time and save them on the host. They are using the “logread” command through ssh, and to limit the amount of duplicated information, we filter the logs associated to their application only. Since the FX30 rebooted, they were not able to gather the other logs around the time the problem occurred.

Since they don’t use the wifi, they though they could deactivate the service.

On their development setup, They deactivated it with

config set /apps/wifiService/startManual false bool

and rebooted the FX30 to test the behaviour.

The first time, They got a cellular data connection, but only in IPv6.
The second time, the modem wasn’t able to connect to the cellular tower. I powered the modem off and checked the SIM, antenna, power connector (loose wire ground can cause weird behavior).
On third and forth attempts all went well.

Since they assume the cellular would always be rmnet_data0, they use that one to enable the data forwarding from the host to the the internet. If the network interface is wlan0 the packets won’t be forwarded since it’s not enabled by default and they didn’t added the rules for the unexpected/unused interface name.

Is it a wrong interface name in the data connection callback?
Would it be safe to disable all the wifiService application?

Please advise.

Thanks

2

do you mean the cellular data somehow creates wlan0?

3

Thanks for your reply. I believe customer disabled the WiFi card and was still having intermittent issues with their cellular connection. Is cellular interface always rmnet_data0? and wlan0 interface always non-cellular(wifi/BT etc.)?

Thanks,
Kalpit

4

I think so, from my testing, I can see rmnet_data0 for the cellular data.

5

thanks. Is “wlan0” interface indicating the Wireless LAN interface (AP mode) in FX30?

6

i think it is the network interface for the WIFI IOT card

7

Thanks but as you may know that Wifi card can be used as wireless LAN (AP mode) or Wireless WAN (Client mode). Which one “wlan0” represents, from name it looks like Wireless LAN interface(AP mode) but wanted to confirm.

8

for client mode, you will still see wlan0.

9

@kkadia

the wlan0 is the interface name which will be the same, the AP or Station mode functionality is from the WiFi service apps

Thanks,

Pankaj Sant