Unable to connect to AT&T after upgrading MFW to v1.1.0

[jbrzozoski]

We had been using an AT&T M1-enabled SIM in one of our development units successfully for quite some time.  After we upgraded that node to MFW v1.1.0, it is no longer able to connect to the cell network.  We tried swapping SIMs around between devices with different firmware versions confirmed that any node still running MFW v1.0.1 is able to connect to the AT&T network using this SIM, and any node running MFW v1.1.0 is not.  I put the SIM in one of our v1.1.0 nodes, loaded up at_client, and turned on as much output as I could.  The relevant error when trying to connect to the network is this:

+CNEC_ESM: 33,0
+CNEC_EMM: 19
+CEREG: 2,"FFFE","FFFFFFFF",7,0,19,"11100000","11100000"
+CEREG: 2,"0411","00F63F11",7,0,19,"11100000","11100000"

It gets the CEREG failure almost immediately and then just sits there doing nothing.  (We waited 15+ minutes)

Again, this failure is using an official AT&T SIM that returns 2 to the AT%XOPERID command.

We are able to connect to the same AT&T cells using v1.1.0 if we put in an MVNO SIM (hologram).

What is the modem doing differently with and without the official AT&T SIM?  Whatever it is doing, it's breaking something in our testing.

[chester314]

Hello.  I do not have a solution but I do have a potentially useful additional data point.

We are also using official AT&T SIMs in southeast USA and modem fw V1.1.0 seems to have broken our ability to connect as well.

After having problems with our app, we simplified to using the link monitor and stock at_client. 

What we saw in all cases is modem fw V1.0.1 getting a complete connection in < 10 seconds while V1.1.0 never connects.

Below is with V1.1.0 (note we get:+CNEC_ESM and +CNEC_EMM messages):

SPM: NS reset vector at 0xde89
SPM: prepare to jump to Non-Secure image.
***** Booting Zephyr OS build v2.0.99-ncs1 *****
The AT host sample started
AT+CFUN=1
OK
AT+CFUN?
+CFUN: 1
OK
AT+CGSN=1
+CGSN: "352656100816191"
OK
AT+CGMI
Nordic Semiconductor ASA
OK
AT+CGMM
nRF9160-SICA
OK
AT+CGMR
mfw_nrf9160_1.1.0
OK
AT+CEMODE?
+CEMODE: 2
OK
AT%XCBAND=?
%XCBAND: (1,2,3,4,5,8,12,13,14,17,18,19,20,25,26,28,66)
OK
AT+CMEE?
+CMEE: 0
OK
AT+CMEE=1
OK
AT+CNEC?
+CNEC: 0
OK
AT+CNEC=24
OK
AT+CGEREP?
+CGEREP: 0,0
OK
AT+CGDCONT?
OK
AT+CGACT?
OK
AT+CGEREP=1
OK
AT+CIND=1,1,1
OK
AT+CEREG=2
OK
AT+CEREG?
+CEREG: 2,4,"FFFE","FFFFFFFF",7
OK
AT%CESQ=1
OK
AT+CESQ
+CESQ: 99,99,255,255,255,255
OK
AT%XSIM=1
OK
AT%XSIM?
%XSIM: 1
OK
AT+CPIN?
+CPIN: READY
OK
AT+CPINR="SIM PIN"
+CPINR: "SIM PIN",3
OK
AT+CIMI
204080813511271
OK
AT+CESQ
+CESQ: 99,99,255,255,255,255
OK
AT+CPINR="SIM PIN"
%CESQ: 43,2,10,1
+CEREG: 2,"9103","0236CE03",7
+CPINR: "SIM PIN",3
OK
AT+CIMI
204080813511271
OK
+CNEC_ESM: 38,0
+CNEC_EMM: 19
%CESQ: 38,1,10,1
%CESQ: 255,0,255,0
+CEREG: 2,"FFFE","FFFFFFFF",7
%CESQ: 255,0,255,0
AT+CESQ
+CESQ: 99,99,255,255,255,255
OK
AT+CFUN?
+CFUN: 1
<snip>
OK
AT+CESQ
+CESQ: 99,99,255,255,255,255
OK
AT+CESQ
+CESQ: 99,99,255,255,255,255
OK
%CESQ: 31,1,4,0
+CEREG: 2,"3319","0ABA3210",7
+CNEC_EMM: 11
%CESQ: 255,0,255,0
+CEREG: 2,"FFFE","FFFFFFFF",7
%CESQ: 34,1,9,1
+CEREG: 2,"3319","0ABA3210",7
AT+CESQ
+CESQ: 99,99,255,255,9,34
OK
+CNEC_ESM: 38,0
+CNEC_EMM: 19
%CESQ: 255,0,255,0
+CEREG: 2,"FFFE","FFFFFFFF",7
%CESQ: 31,1,7,1
+CEREG: 2,"3319","0ABA3210",7
AT+CESQ
+CESQ: 99,99,255,255,7,31
OK
AT+CESQ
+CESQ: 99,99,255,255,7,31
OK

Here is with V1.1.0

SPM: NS reset vector at 0xde89
SPM: prepare to jump to Non-Secure image.
***** Booting Zephyr OS build v2.0.99-ncs1 *****
The AT host sample started
AT+CFUN=1
OK
AT+CFUN?
+CFUN: 1
OK
AT+CGSN=1
+CGSN: "352656100816191"
OK
AT+CGMI
Nordic Semiconductor ASA
OK
AT+CGMM
nRF9160-SICA
OK
AT+CGMR
mfw_nrf9160_1.0.1
OK
AT+CEMODE?
+CEMODE: 2
OK
AT%XCBAND=?
%XCBAND: (1,2,3,4,5,8,12,13,14,17,18,19,20,25,26,28,66)
OK
AT+CMEE?
+CMEE: 0
OK
AT+CMEE=1
OK
AT+CNEC?
+CNEC: 0
OK
AT+CNEC=24
OK
AT+CGEREP?
+CGEREP: 0,0
OK
AT+CGDCONT?
+CGDCONT: 0,"IP","m2m64.com.attz","10.71.183.29",0,0
OK
AT+CGACT?
+CGACT: 0,1
OK
AT+CGEREP=1
OK
AT+CIND=1,1,1
OK
AT+CEREG=2
OK
AT+CESQ
+CESQ: 99,99,255,255,255,34
OK
AT+CEREG?
+CEREG: 2,1,"3319","0ABB1011",7
OK
AT+COPS=3,2
OK
AT+COPS?
+COPS: 0,2,"310410",7
OK
AT%XCBAND
%XCBAND: 17
OK
AT+CGDCONT?
+CGDCONT: 0,"IP","m2m64.com.attz","10.71.183.29",0,0
OK
AT+CGACT?
+CGACT: 0,1
OK
AT%CESQ=1
OK
AT+CESQ
+CESQ: 99,99,255,255,255,34
OK
AT%XSIM=1
OK
AT%XSIM?
%XSIM: 1
OK
AT+CPIN?
+CPIN: READY
OK
AT+CPINR="SIM PIN"
+CPINR: "SIM PIN",3
OK
AT+CIMI
310170833560137
OK

I can open another ticket if requested but since it seems like it may be the same issue I'm starting here.  Please advise if there is anything we can do to help troubleshoot this.  Thank you in advance for any and all support.