SIM7020E NB-IoT module doesn't connect via HTTP or MQTT

Projects Networking, Protocols, and Devices
1

Hi everyone, I'm using a SIM7020E with a Vodafone DE card. I can connect successfully to their server but fail to establish any connections via HTTP or MQTT. I have the same problem with Arduino MKR NB 1500.
I am doing something wrong? Here is the AT command list for SIM7020E -
AT

11:21:28.464 -> OK
AT+cfun=0

11:21:36.483 -> +CPIN: NOT READY

11:21:36.530 -> OK
AT+CFUN=1

11:21:44.302 -> OK

11:21:44.573 -> +CPIN: READY
AT*MCGDEFCONT="IP","nb.inetd.gdsp"

11:22:16.276 -> OK
AT+COPS=1,2,"26202"

11:22:30.516 -> OK
AT+CGCONTRDP

11:22:43.888 -> +CGCONTRDP: 1,5,"nb.inetd.gdsp","10.48.34.254.255.255.255.0",,"10.105.16.254","10.105.144.254",,,,,1430
11:22:43.988 ->
11:22:43.988 -> OK
at+CIPPING="8.8.8.8"

11:24:50.654 -> OK
+CIPPING: 1,8.8.8.8,4,47
+CIPPING: 2,8.8.8.8,3,47
+CIPPING: 3,8.8.8.8,3,47
+CIPPING: 4,8.8.8.8,8,47
AT+CHTTPCREATE="http://www.sim.com/"

11:30:24.092 -> +CHTTPCREATE: 0
11:30:24.092 ->
11:30:24.092 -> OK
AT+CHTTPCON=0

11:31:14.565 -> ERROR

Do you guys have any suggestions or solutions to this problem?

Thanks and greetings from the land of Oktoberfest! :slight_smile:

2

Why do you ping a Google IP but then try to connect to a Chinese web server? Try to connect to https://www.google.com/ or something similar or ping the Chinese IP before that.

3

I have the same error when I try to connect to the Google server. Maybe there's a problem with the DNS server?

at

10:13:57.384 -> OK
at+cfun=0

10:14:03.249 -> +CPIN: NOT READY
10:14:03.249 ->
10:14:03.249 -> OK
at+cfun=1

10:14:07.417 -> OK

10:14:07.682 -> +CPIN: READY
AT*MCGDEFCONT="IP","nb.inetd.gdsp"

10:14:16.210 -> OK
AT+COPS=1,2,"26202"

10:14:23.697 -> OK
AT+CGCONTRDP

10:14:28.673 -> +CGCONTRDP: 1,5,"nb.inetd.gdsp","10.48.4.225.255.255.255.0",,"10.105.16.254","10.105.144.254",,,,,1430
10:14:28.724 ->
10:14:28.724 -> OK
at+CIPPING="8.8.8.8"

10:14:55.529 -> OK
+CIPPING: 1,8.8.8.8,9,47
+CIPPING: 2,8.8.8.8,9,47
+CIPPING: 3,8.8.8.8,3,47
+CIPPING: 4,8.8.8.8,3,47
AT+CHTTPCREATE="http://www.google.com/"

10:15:15.687 -> +CHTTPCREATE: 0
10:15:15.687 ->
10:15:15.687 -> OK
AT+CHTTPCON=0

10:16:02.337 -> ERROR

4

Try reading out the DNS server the module is using. Maybe vodafone is blocking some sites (although Google would be a very bad choice) or has such a complex network setup that simple requests are not going through. Read out as much information as possible to get an overview of the situation.