Bg95 nb-iot mqtt aws +qmtopen: 0, -1

Hello,
We are using BG95-M3 module for communication with AWS by MQTT.
It’s working well in EDGE and eMTC but not with NB-IoT. Can’t find why.

Here is log in EDGE:
AT+QNWINFO

+QNWINFO: “EDGE”,“20810”,“GSM 1800”,84

OK
AT+QSSLCFG=“cacert”,2,“cacert.pem”

OK
AT+QSSLCFG=“clientcert”,2,“client.pem”

OK
AT+QSSLCFG=“clientkey”,2,“user_key.pem”

OK
AT+QSSLCFG=“seclevel”,2,2

OK
AT+QSSLCFG=“sslversion”,2,4

OK
AT+QSSLCFG=“ciphersuite”,2,0XFFFF

OK
AT+QSSLCFG=“ignorelocaltime”,2,1

OK
AT+QMTCFG=“ssl”,0,1,2

OK
AT+QMTCFG=“version”,0,4

OK
AT+QMTOPEN=0,"**************.amazonaws.com",8883

OK

+QMTOPEN: 0,0
AT+QMTCONN=0,“toto”

OK

+QMTCONN: 0,0,0

And in NB-IoT:
AT+QNWINFO

+QNWINFO: “NBIoT”,“20810”,“LTE BAND 20”,6310

OK
AT+QSSLCFG=“cacert”,2,“cacert.pem”

OK
AT+QSSLCFG=“clientcert”,2,“client.pem”

OK
AT+QSSLCFG=“clientkey”,2,“user_key.pem”

OK
AT+QSSLCFG=“seclevel”,2,2

OK
AT+QSSLCFG=“sslversion”,2,4

OK
AT+QSSLCFG=“ciphersuite”,2,0XFFFF

OK
AT+QSSLCFG=“ignorelocaltime”,2,1

OK
AT+QMTCFG=“ssl”,0,1,2

OK
AT+QMTCFG=“version”,0,4

OK
AT+QMTOPEN=0,"**************.amazonaws.com",8883

OK

and nothing more, if I reboot by “AT+CFUN=1,1” I see +QMTOPEN: 0,-1

It’s working well even in NB-IoT on local MQTT server.

Also I’m using eval board with:
AT+QGMR
BG95M3LAR02A03_01.009.01.009

Where can I find latest firmware? Can this be related?

Thank you, have a good day,
Thomas

AT+Qwinfo can query the neteork environment only , it can not identify the PDP status , before you connect the AWS mqtt
pls check the below two cmd first :slight_smile:

  1. AT+cereg? //check the register status

  2. AT+QIACT? //check the PDP context

Hello Stephen,
Thank you for answering.
Both commands are OK for me:
RDY

APP RDY
AT+QNWINFO

+QNWINFO: “NBIoT”,“20810”,“LTE BAND 20”,6310

OK
AT+CEREG?

+CEREG: 0,1

OK
AT+QIACT?

OK
AT+QSSLCFG=“cacert”,2,“cacert.pem”

OK
AT+QSSLCFG=“clientcert”,2,“client.pem”

OK
AT+QSSLCFG=“clientkey”,2,“user_key.pem”

OK
AT+QSSLCFG=“seclevel”,2,2

OK
AT+QSSLCFG=“sslversion”,2,4

OK
AT+QSSLCFG=“ciphersuite”,2,0XFFFF

OK
AT+QSSLCFG=“ignorelocaltime”,2,1

OK
AT+QMTCFG=“ssl”,0,1,2

OK
AT+QMTCFG=“version”,0,4

OK
AT+CEREG?

+CEREG: 0,1

OK
AT+QIACT?

OK
AT+QMTOPEN=0,"***************.amazonaws.com",8883

OK

But nothing happened after this :frowning:

Any hints ? Tell me if you need me to check other things :slight_smile:

Please excute AT+QIACT=1 and then excute AT+QIACT? to check whether the IP address can be obtained after the PDP is activated.
If you can get the IP, try AT+QMTOPEN again.You can wait a while to confirm the URC results:

Hi Winnie all looks good to me but still can’t connect to AWS in NB-IoT:

RDY

APP RDY
AT+QIACT=1

OK
AT+QIACT?

+QIACT: 1,1,1,“10.231.149.92”

OK
AT+QNWINFO

+QNWINFO: “NBIoT”,“20810”,“LTE BAND 20”,6310

OK
AT+QSSLCFG=“cacert”,2,“cacert.pem”

OK
AT+QSSLCFG=“clientcert”,2,“client.pem”

OK
AT+QSSLCFG=“clientkey”,2,“user_key.pem”

OK
AT+QSSLCFG=“seclevel”,2,2

OK
AT+QSSLCFG=“sslversion”,2,4

OK
AT+QSSLCFG=“ciphersuite”,2,0XFFFF

OK
AT+QSSLCFG=“ignorelocaltime”,2,1

OK
AT+QMTCFG=“ssl”,0,1,2

OK
AT+QMTCFG=“version”,0,4

OK
AT+QMTOPEN=0,"*********.iot.eu-west-1.amazonaws.com",8883

OK

+QMTOPEN: 0,-1 (after looong time)

Could this be because of incompatibility between AWS and my operator (SFR France) ? Most likely this is not related to Quectel because everything is OK on local server but maybe you had feedback?

Hi,
You can change the SIM card and try again,If that doesn’t work, you might need to grab log to analysis.
Please contact support@quectel.com for more assistance.

Hi Thomas,
I have the exact same issue: MQTT is working fine for GSM and eMTC. When using NB-IoT, it fails on the QMTOPEN step (response: +QMTOPEN: 0,-1).
Did you find a solution?