AT&T SIM is not connecting to LTE or losing connection unexpectedly on Sierra EM7565 modem

AT&T SIM is not connecting to LTE or losing connection unexpectedly on Sierra EM7565 modem

Sierra EM7565 modems where the AT&T carrier profile is utilizing the 01.14.02.00 firmware may experience connectivity issues including a failure to connect or unexpected modem resets.  In Nodegrid OS, this profile is identified as 01.14.02.00_ATT.  Here are steps to check the current AT&T carrier profile installed:

GUI:

  1. Login into the web interface
  2. Navigate to Network :: Wireless Modem :: Global
  3. Check the box for the Channel of the modem to check
  4. Check the Firmware button
  5. Review the _ATT entry in the output

CLI:
  1. Log into the command line interface
  2. Run: cd /settings/wireless_modem/global/
  3. cd to the specific modem to check
    1. Example: cd Channel-A
  4. Run: cd firmware
  5. Run: show
  6. Review the _ATT entry in the output

Example:

[admin@nodegrid firmware]# show
  build id              type                   unique id
  ====================  =====================  ===========
  01.08.04.00           Firmware Image                    
  01.07.02.00           Firmware Image                    
  01.09.04.00           Firmware Image                    
  01.14.02.00_ATT       Carrier Configuration  002.047_002
...

When experiencing connectivity issues while this profile is present and using an AT&T SIM, the solution is to update the firmware to use the AT&T carrier profile which refers to the 1.14.13.00 firmware or newer:



Here are the steps to download and update the Sierra EM7565 firmware: Installing Firmware for LTE Modem
 
We have identified a batch of modems which shipped with the affected profile by default.  The affected modems can be identified by their IMEI number as this indicates the what firmware was shipped with the modem when it was manufactured.  This makes it possible to proactively identify these modems and update the firmware as appropriate.  Check the 8th through 10th digits of the modem's IMEI number; if they are 033 or 034 updating the firmware may be needed when installing an AT&T SIM. Here is an example:

 

In case you still having connectivity issues where the SIM shows “Not Registered” after the firmware has been upgrade.d We may need to “communicate” with the modem using microcom and set some parameters with the AT commands  (assuming there exists network Connection for Broadband, and APN is m2m005041.attz)

 

Here are the steps:

 

1.          Log in to Nodegrid as admin, and go to root shell (shell sudo su -)

2.          Stop Modem manager: /etc/init.d/m2mgmtd stop

3.          Open microcom to the modem’s “console”:  microcom /dev/ttyUSB2

4.          Type  ate1   and hit ENTER (you will now see what you are typing – ate1 is to enable echo, and for every command you should see OK)

5.          Now you will be able to see what you are typing. Then type at+cgdcont? d and hit ENTER

6.          It should display 2 lines as follows:

at+cgdcont?

+CGDCONT: 1,"IPV4V6","broadband","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0

+CGDCONT: 4,"IPV4V6","attm2mglobal","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0

OK

7.          Type at+cfun=0

at+cfun=0

OK

8.          Type at+cgdcont=1,"IP","m2m005041.attz"

at+cgdcont=1,"IP","m2m005041.attz"

OK

9.          Type at&W

at&W

OK

10.       Type at+cgdcont?  To confirm the change was effective.

at+cgdcont?

+CGDCONT: 1,"IP","m2m005041.attz","0.0.0.0",0,0,0,0

+CGDCONT: 4,"IPV4V6","attm2mglobal","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0

 

OK

 

11.       Type at+cfun=1

at+cfun=1

OK

 

12.       Type at+cops?

at+cops?

+cops: 0,0,"AT&T",7

 

OK

 

13.       Exit microcom with CTRL-X

Start Modem Manager: /etc/init.d/m2mgmtd


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