[Fx30] Data connection parameters changing


#1

Hello,

I am having a problem of the data connection parameters changing.
I’m using the Linux console to enter commands.

  1. I set the data connection parameters using the “cm data” interface
    Here are parameters after the configuration :
root@fx30:~# cm data
    Index:      1
    APN:        orange.m2m
    PDP Type:   IPV4V6
    Connected:  no
  1. After some connection attempt, I sometime find the setting changing to a different configuration.
    It seem to happen under bad network conditions.
    The parameters I find are:
root@fx30:~# cm data
    Index:      1
    APN:        orange.fr
    PDP Type:   IPV4V6
    Connected:  no
    Auth type:  PAP
    User name:  orange
    Password:   orange

Here are some information about the Fx30 I’m using:

$ cm info
    Device:     FX30
    IMEI:       353984080225020
    FSN:        LL744101561310
    Firmware:   SWI9X15Y_07.11.22.00 r33729 CARMD-EV-FRMWR1 2017/01/11 18:04:06
    Bootloader: SWI9X15Y_07.11.22.00 r33729 CARMD-EV-FRMWR1 2017/01/11 18:04:06
    priIdPn:    9906645
    priIdRev:   01.02
    skuId:      1103214
root@fx30:~# microcom -E /dev/ttyAT
    AT!FWD?ALVER
        R13.1.2.004
        OK
    AT!FWD?HFSN
        Q575210024041017
        OK
root@fx30:~# fwupdate query
    Connecting to service ...
    Firmware Version: SWI9X15Y_07.11.22.00 r33729 CARMD-EV-FRMWR1 2017/01/11 18:04:06
    Bootloader Version: SWI9X15Y_07.11.22.00 r33729 CARMD-EV-FRMWR1 2017/01/11 18:04:06
    Linux Version: 3.14.29ltsi-a00e464379_3f15cd39ad #2 PREEMPT Mon Feb 20 11:11:17 PST 2017
    FX30 Version: R13.1.2.004

I see this problem with Orange M2M SIM cards, I never saw it with SWI SIM cards.
Where is this configuration of the parameters coming from? Is-it a default setting configured in the modem, or are those automatically configured by the GSM network?

I’m worried that on some countries this parameter change could prevent me from connecting the data channel.

Could you share some information on what could be the reason of this parameter change?

Best regard, Christian.


#2

Hi Christian,
We’ll investigate the issue and get back to you. I apologize for the issue you’re observing.

Could you please confirm:

  1. How are you establishing the data session? ie, are you using “cm data connect”?
  2. Is there any chance you recorded the IMSI before and after the APN changed?
  3. Did the APN change as a result of failed connection attempts? ie, there were no reboots, firmware updates, carrier switch, or SIM switch?

BR,
Chris


#3

Hello Chris,

I do use “cm data connect” to start the connection attempt.
There are no reset, reboot, usb disconnection, SIM removal during the manipulation.
Below is a trace captured in one go. I have interrupted the connection attempt manually (with Ctrl+C) after some minutes, then the APN has changed. As you can see the SIM IMSI has not changed.

root@fx30:~# cm data
    Index:      1
    APN:        orange.m2m
    PDP Type:   IPV4V6
    Connected:  no
root@fx30:~# cm sim info
    Type:       EXTERNAL_SLOT_1
    ICCID:      89330123603000540280
    Home Network Operator: Orange F
    IMSI:       208019802901822
    Phone Number:
root@fx30:~# cm data connect
    ^C
root@fx30:~# cm data
    Index:      1
    APN:        orange.fr
    PDP Type:   IPV4V6
    Connected:  yes
    Auth type:  PAP
    User name:  orange
    Password:   orange
root@fx30:~# cm sim info
    Type:       EXTERNAL_SLOT_1
    ICCID:      89330123603000540280
    Home Network Operator:
    IMSI:       208019802901822
    Phone Number:
root@fx30:~# cm radio
    Power:      ON
    Current Network Operator:
    RAT:        UMTS network (LE_MRC_RAT_UMTS)
    Status:     Registered, home network (LE_MRC_REG_HOME)
    Signal:     Weak signal strength (2)
root@fx30:~#

Remark that the “Home Network Operator” information returned by the “cm sim info” command has been lost after the APN change…

Best regards, Christian.


#4

Hi Christian,
Thank you for the information. We suspect there is an issue in the Legato modemServices and are currently investigating, but the issue is difficult to reproduce.

If possible, could you please provide:

  1. A log when the issue occurs
  2. Some info on how you caused the issue to occur. ie, more precise amount of time before you hit ^C. Clarification on what you mean by “bad network conditions”

BR,
Chris


#5

Hello Chris,

When I say “bad network condition”, I mean that I saw this problem appears more on manipulations without a metallic ground part under the antenna. To reproduce the problem I used to disconnect partly (the metallic wire part above the magnetic base) the antenna.

It took me quite some time today (some hours) to reproduce the problem. The conditions are a bit different as this time the antenna was totally connected.
For this manipulation, I was using a second SSH connection to check the “$> cm data” result from time to time, while the main ssh terminal was waiting on the “$cm data connect” command.

For this manipulation I performed the following:

  • On the first terminal: execute several basic functions to capture the conditions

> cm info", "> cm sim info”, …

  • On the first terminal: execute the data connect command:

“$> cm data connect”

  • On the second terminal: check the return of the “$> cm data” command to check if the parameters have changed
  • On the second terminal: I have modified the PDP parameter from IPV4V6 to IPV4 with the command:

“$> cm data pdp IPV4”

  • Shortly (~15 seconds) after the PDP change, the data connection establish and the parameters have changed.

I attach a log captured during the manipulation.

Best regards, Christian.

Pb-ConnectionParameterChange-10122018-2.zip (28.6 KB)


#6

Hi Christian,
We haven’t been able to reproduce the issue yet, but suspect the cause is in the modemServices incorrectly calling the SetDefaultAPN function.

Do you have the capability of rebuilding Legato with this function reduced to a stub for testing?

BR,
Chris