Error connecting to mqtt server using quectel bg96 module

IoT Modules LPWA Module
1

i have been able to connect to azure-iot-hub and publish and subscribe to topics while using self-signed X509 certs. i used bg96 module to connect to my azure iot hub. Now i have set up device provisioning service and i am trying to connect to my device global endpoint. i am using the same ssl configuration as before but i am unable to open mqtt connection.

i get this error mqtt network open fail

+QMTOPEN: 1,-1

here is the complete output

-> ATI


<- Quectel
<- BG96
<- Revision: BG96MAR02A07M1G
<- 
<- OK
Quectel
BG96
Revision: BG96MAR02A07M1G

AT+CPIN?


-> AT+CPIN?


<- +CPIN: READY


-> AT+QICSGP=2,1,"ZONG","","",3


<- OK


-> AT+QIACT=2


<- OK


-> AT+QICSGP=2,1,"ZONG","","",3


<- OK


-> AT+CGPADDR=2


<- +CGPADDR: 2,100.110.43.143

 
<- OK


APN OK: The IP address is 100.110.43.143


-> AT+QSSLCFG="sslversion",0,3


<- OK


-> AT+QSSLCFG="ciphersuite",0,0XFFFF


<- OK


-> AT+QSSLCFG="negotiatetime",0,300


<- OK


-> AT+QFUPL="ca_cert.pem",1282


Send Data len :1282


+QFUPL: 1282,5155


<- OK


-> AT+QFUPL="client_cert.pem",1188


Send Data len :1188


+QFUPL: 1188,707e


<- OK


-> AT+QFUPL="client_key.pem",1732


Send Data len :1732


+QFUPL: 1732,595e


<- OK


-> AT+QSSLCFG="seclevel",0,2


<- OK


-> AT+QSSLCFG="cacert",0,"ca_cert.pem"


<- OK


-> AT+QSSLCFG="clientcert",0,"client_cert.pem"


<- OK


-> AT+QSSLCFG="clientkey",0,"client_key.pem"


<- OK


-> AT+QSSLCFG="ignorelocaltime",0,1


<- OK


AT+QSSLCFG="ignorelocaltime",0


+QSSLCFG: "ignorelocaltime",0,1


OK


SSL OK: The ssl were successfully initialized.


-> AT+QMTCFG="version",1,4


<- OK


-> AT+QMTCFG="pdpcid",1,2


<- OK


-> AT+QMTCFG="keepalive",1,150


<- OK


-> AT+QMTCFG="session",1,1


<- OK


Config the MQTT Parameter Success!


AT+QMTCFG="ssl",1,1,0


OK

AT+QMTOPEN=1,"global.azure-devices-provisioning.net",8883

OK


+QMTOPEN: 1,-1
2

before you do “AT+QMTOPEN”，pls send AT+QIACT？ to check that ， if the PDP has been activated successfully ， thanks

https://cnquectel-my.sharepoint.com/:f:/g/personal/america-fae_quectel_com/EhnjdN0lxvhCmWmwZnYE05YB4NS6IvzBfwNGk99QcarP7g?e=iE7cAY

3

thanks for the reply…
i have checked the link you mentioned in your reply. in these examples you are connecting directly to iot hub but i am trying to connect to azure dps. as i said i can connect to my iot hub successfully this error occurs only when i am trying to connect to dps global endpoint that is global.azure-devices-provisioning.net. i am trying to register my device there. can you please send me any example of that?

here the output of AT+QIACT？before AT+QMTOPEN as you can see pdp context is active but still not connecting.

i have changed the pdp, ssl and mqtt context according to whats recommended in the mqtt application note.

complete output

<- Quectel
<- BG96
<- Revision: BG96MAR02A07M1G
<- 
<- OK
Quectel
BG96
Revision: BG96MAR02A07M1G

-> AT+CPIN?


<- +CPIN: READY
-> AT+QICSGP=1,1,"ZONG","","",3


<- OK
-> AT+CGPADDR=1


<- +CGPADDR: 1,0.0.0.0
<- 
<- OK
-> AT+QIACT=1


<- ERROR
<- AT+QICSGP=1,1,"ZONG","","",3
-> AT+QICSGP=1,1,"ZONG","","",3


<- OK
-> AT+CGPADDR=1


<- +CGPADDR: 1,0.0.0.0
<- 
<- OK
-> AT+QIACT=1


<- OK
-> AT+QICSGP=1,1,"ZONG","","",3


<- OK
-> AT+CGPADDR=1


<- +CGPADDR: 1,100.65.228.150
<- 
<- OK
APN OK: The IP address is 100.65.228.150


-> AT+QSSLCFG="sslversion",2,3


<- OK
-> AT+QSSLCFG="ciphersuite",2,0XFFFF


<- OK
-> AT+QSSLCFG="negotiatetime",2,300


<- OK
-> AT+QFUPL="ca_cert.pem",1282


<- +CME ERROR: 407
<- AT+QFDEL="ca_cert.pem"
-> AT+QFDEL="ca_cert.pem"


<- OK
-> AT+QFUPL="ca_cert.pem",1282


<- CONNECT

Send Data len :1282
+QFUPL: 1282,5155
<- 
<- OK
-> AT+QFUPL="client_cert.pem",1188


<- +CME ERROR: 407
<- AT+QFDEL="client_cert.pem"
-> AT+QFDEL="client_cert.pem"


<- OK
-> AT+QFUPL="client_cert.pem",1188


<- CONNECT
Send Data len :1188
+QFUPL: 1188,707e
<- 
<- OK
-> AT+QFUPL="client_key.pem",1732


<- +CME ERROR: 407
<- AT+QFDEL="client_key.pem"
-> AT+QFDEL="client_key.pem"


<- OK
-> AT+QFUPL="client_key.pem",1732


<- CONNECT
Send Data len :1732
+QFUPL: 1732,595e
<- 
<- OK
-> AT+QSSLCFG="seclevel",2,2


<- OK
-> AT+QSSLCFG="cacert",2,"ca_cert.pem"


<- OK
-> AT+QSSLCFG="clientcert",2,"client_cert.pem"


<- OK
-> AT+QSSLCFG="clientkey",2,"client_key.pem"


<- OK
-> AT+QSSLCFG="ignorelocaltime",2,1


<- OK


SSL OK: The ssl were successfully initialized.


-> AT+QMTCFG="version",0,4


<- OK
-> AT+QMTCFG="pdpcid",0,1


<- OK
-> AT+QMTCFG="keepalive",0,150


<- OK
-> AT+QMTCFG="session",0,1


<- OK
Config the MQTT Parameter Success!

-> AT+QMTCFG="ssl",0,1,2


<- OK
Enable the SSL Success!
AT+QIACT?


+QIACT: 1,1,1,"100.65.228.150"

OK
AT+QMTOPEN=0,"global.azure-devices-provisioning.net",8883

OK

+QMTOPEN: 0,-1
4

just so you know i have already verified that my certs are working using mqttbox and by connecting to my iot-hub using same certs successfully. so there is no problem with my certificates.

but there is one thing i can open network when i disable ssl using the AT+QMTCFG="ssl"0,0,2. but then i cannot establish connection using AT+QMTCONN because my mqtt server requires ssl/tls secure connection. again if there is any working example you can send me to connect to azure dps global endpoint that would be great.

5

@Stephen.Li-Q any updates on the question i asked… did you try it yourself??

6

sorry , i have no experience to connect azure iot DPS service ， but i found one at log about this from my colleague ， i attached it with the below link ,

https://cnquectel-my.sharepoint.com/:f:/g/personal/america-fae_quectel_com/ElgF0LjgsU9JgrrWNwdfNqkBpXzi_tD10DHRs2NyQpMthA?e=CXM8Jh

8

Thanks for the effort @Stephen.Li-Q . i have contacted to Quectel’s FAE through support@quectel.com and i hope they will be able to solve my problem.

9

Hello,
Sorry for reopening this topic but i have exactly the same problem.
I can open, connect , send and receive data with mosquitto broker using SSL on port 8884.
But when I want to do the same with eventgrid.azure.net I can’t open, it returns +QMTOPEN: 0,-1

Do you found a solution ?
What was the problem ?

It will be very helpfull.

Thanks

10

Hi, As far as remember the issue was with the module’s firmware that I was using. In my case I was using BG96, and it had older firmware version which was causing this issue. Try upgrading the firmware.
Also keep in mind that this problem can happen from several reasons, but you can try my solutions to see if you have same problem as me

11

Ok…Thanks.
I will try to update it …i have the diff file between my actual firmware and the new one but i don’t know what to do?
Quectel say i have to put the file on an http server and make AT+QFOTAD but i don’t have any http server.
Do you know how to procede ?