EC200U Connecting to MQTT broker

IoT Modules LTE Standard Module
1

I am facing this issue specifically with only one provider JIO in India as JIO only supports IPv6.
I am using EC200U-CN module & MQTT AT commands for communication.

In my application I am setting the PDP context using AT+QICSGP=1,3,“jionet” and activating it using AT+QIACT=1. After this I get an IPv6 address. I am able to read it using AT+QIACT?.

After this I want to connect to an mqtt broker that supports only IPv4 using the command AT+QMTOPEN=0,“14.245.123.116”,1883 but I am unable to connect to the server and I always get +QMTOPEN: 0,4 as the response.

Please let me know if there is any way I can solve this problem.

PS: Using JIO I am able to communicate with AWS and Hive MQTT brokers with & without TLS. I am just unable to communicate with this server. So if anyone can even suggest how I can debug the problem even that helps.

Thanks in advance.

2

pls run

AT+CEREG?
AT+CGDCONT?
AT+CGPADDR

3

Hi Herbert,
Thanks for your response.
I would like to send you the response of the above mentioned commands but I was experiementing with the module by setting the PDP context and activating it using commands AT+QICSGP=1,3,“jionet” & AT+QIACT=1 & AT+QIDEACT=1.
Now for some reason I see that the modem is not able to detect the SIM card. (It was working earlier so the hardware is correct).
When I run AT+CPIN? I now always get +CME ERROR: 10 as response.

I tried to restore the module to factory defaults using AT&F0 but still the modem now doesn’t detect the SIM card and I also do not see the power on the VDD_SIM pin.

4

Haha, I think you need to troubleshoot the SIM card connection first

5

Any pointers you would like to give from where to start? because it seems that the modem got bricked for some reason.

6

IPv6 addresses can not connect to IPv4 servers. You should reach your broker and tell them to register their IPv6 to the DNS servers.

7

The network will de-register your device when you try to force connect using IPv4 on JIO. modem will not be able to register to the network after you try to get IPv4 address forcibly on JIO.

8

Hi Herbert,
I am using a different modem now where my SIM card detects.

Following is the response to your commands:
AT+CEREG?

+CEREG: 0,1

OK
AT+CGDCONT?

+CGDCONT: 1,“IPV4V6”,“jionet”,“0.0.0.0,2409:40F0:11C:F101:8000::”,0,0
+CGDCONT: 3,“IPV4V6”,“”,“0.0.0.0,0:0:0:0:0:0:0:0”,0,0

OK
AT+CGPADDR

+CGPADDR: 1,“0.0.0.0,2409:40F0:11C:F101:8000::”
+CGPADDR: 3,“0.0.0.0,0:0:0:0:0:0:0:0”

OK

9

This log indicates that your device has successfully registered with the network and successfully obtained the IPV6 address, and you need to connect to the IPV6 server

10

Hi Maharshi,
We will require NAT64 to connect IPV6 based devices to IPV4 based servers. I had done that in the past but not using a cellular network. That’s why I am asking this question here.

11

No, no, you may be using NAT64 on your router, but the network is not able to support this method, you need to upgrade your server to support IPV6

12

OK. Thanks for the clarification.

13

The problem with the JIO is that it gives only IPv6 addresses mostly(IPv4 if you are lucky).
I have similar experiences with JIO, try with different operators. VI and Airtel give IPv4 addresses when you have set the modem to get IPv4 addresses only.

14

can any one tell me. can we use mqtt TLS 8883 port connection by using EC200U - CN 4G module

15

Yes. It works with the settings that you mentioned. We were able to connect to all standard MQTT brokers using it.