nRF9160-DK , Modem_shell demo , ppp unable to access the Internet

[JackyChen]

Hello,guys

I build nrf9160-dk modem_shell demo as cmd '$ west build -b nrf9160dk_nrf9160ns ' and then '$ west flash ', after the system running up, I try to ping baidu website，it works as follow picture.

And then I rebuild the Modem_shell demo with cmd ' $ west build -p -b nrf9160dk_nrf9160_ns -d build -- -DOVERLAY_CONFIG=overlay-ppp.conf' for supporting ppp function. After the system running up, I try to ping baidu website again，it works as follow picture and it work failed.

I can capture any data from another serial, I guess VCOM0 serial is shell and VCOM2 serial is ppp channel.

To test my guess，I plugged nrf9160-DK board into my Ubuntu virtual machine and disable Ubuntu network. Use minicom tool to connect VCOM0 and open nrf9160-DK shell in A terminal, set the custom configuration for PPP uart with cmd 'ppp uartconf -b 115200' . New B terminal for ppp connection , type cmd ' $sudo pppd -detach /dev/ttyACM2 115200 DK-ip:Ubuntu-ip noauth nocrtscts local ' , then A terminal return "Dial up connection up" . New C terminal and type cmd ' ifconfig ' , I can see ppp0 and it's ip ,I try to ping baidu website,it work as follow picture.

it can't access the Internet ? why ? Did I operate wrong? Please point out my mistakes.

The version of modem_fw I use is 1.3.0 , ncs version is 1.7.0.

[Håkon Alseth]

Hi,

 

You are unfortunately running into a known issue with NCS v1.7.0:

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/known_issues.html?v=v1-7-0#other-issues

 

Issue is described here:

https://github.com/zephyrproject-rtos/zephyr/issues/38516

 

While a fixed is posted in this PR:

https://github.com/zephyrproject-rtos/zephyr/pull/38517

 

Could you try applying the above PR and see if it works better on your end?

 

Kind regards,

Håkon

[JackyChen]

Hello Håkon, thanks for your technical support.

yep, I merge this commit

https://github.com/zephyrproject-rtos/zephyr/pull/38517/commits/4ecaebf2b04fd48a1def8f8adf7bd3cc1528c482

and do the experiment again. Unfortunately, my VM-Ubuntu unable to access the network, it still doesn't work.

Best wish.

Jackychen

[Håkon Alseth]

Hi,

 

Could you share the error log? I tested this locally as well, and I was able to successfully connect and ping a server.

 

Kind regards,

Håkon

[JackyChen]

Hi,

When I connect the PC, log as follow.

[JackyChen]

When I type cmd 'AT+CGCONTRDP=0 ' ,

it shows 

+CGCONTRDP: 0,,"cmiot","","",

OK

It can't get the dns. Do you have relevant experience to guide the reason？

Best wish.

Jackychen

[Håkon Alseth]

Hi,

 

Are you able to run any TCP based samples with your SIM card?

For instance: https://github.com/nrfconnect/sdk-nrf/tree/master/samples/nrf9160/mqtt_simple

 

I am unfortunately not able to tell you if that APN is correct or not. I would recommend that you ask your network provider about what they support on NB1 (TCP/UDP/DNS etc)

 

Kind regards,

Håkon

[JackyChen]

Hi，

I checked with the carrier，China does not support LTE-M networks at present，So I do the nrf9160/mqtt_simple test  is useless.

Can you do this test: running modem_shell demo, using NB1, connect to pc,verify the PPP network works properly in NB1 mode ？

Thanks,

Jackychen

[Håkon Alseth]

Hi,

 

Could you test mqtt_simple with nb1? If that example also fails on DNS, it might be related to the network.

 

Kind regards,

Håkon

[JackyChen]

Hi,

em.....

I don't know how to set using NB1 when test mqtt_simple. I didn't see any introduction in https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/nrf9160/mqtt_simple/README.html#building-and-running .

When I program the mqtt_simple to my DK board, the uart output log is:

SPM: NS MSP at 0x20019b70
SPM: NS reset vector at 0x13d6d
SPM: prepare to jump to Non-Secure image.
*** Booting Zephyr OS build v2.6.99-ncs1-10-g7b6343a709b5 ***
[00:00:00.207,244] <wrn> at_notif: Already initialized. Nothing to do
[00:00:00.207,336] <inf> mqtt_simple: The MQTT simple sample started
[00:00:00.207,336] <inf> mqtt_simple: Disabling PSM and eDRX
[00:00:00.208,251] <inf> mqtt_simple: LTE Link Connecting...
+CEREG: 4
+CEREG: 0
[00:10:00.257,141] <inf> lte_lc: Network connection attempt timed out
[00:10:00.280,792] <inf> lte_lc: Using fallback network mode
+CEREG: 2,"1D26","0AC23D3E",9
+CSCON: 1
+CEREG: 1,"1D26","0AC23D3E",9,,,"11100000","11100000"
[00:10:10.128,234] <inf> mqtt_simple: LTE Link Connected!
[00:10:10.128,479] <err> mqtt_simple: getaddrinfo failed: -2
[00:10:10.128,479] <err> mqtt_simple: Failed to initialize broker connection
[00:10:10.128,479] <err> mqtt_simple: client_init: -10
+CSCON: 0
+CEREG: 1,"1D28","0D1E5A42",9,,,"11100000","11100000"
+CSCON: 1
+CSCON: 0
+CEREG: 1,"1D26","0AC23D3E",9,,,"11100000","11100000"
+CEREG: 1,"1D28","0D1E5A42",9,,,"11100000","11100000"
+CEREG: 1,"1D26","0AC23D3E",9,,,"11100000","11100000"
+CEREG: 1,"1D28","0D1E5A41",9,,,"11100000","11100000"
+CEREG: 1,"1D26","0AC23D3E",9,,,"11100000","11100000"

It looks like I can't get an IP address.

[Håkon Alseth]

Hi,

 

You need to contact your network provider and ask what is supported in their network. I also see that you are not getting PSM from the network, and you're in total connected to three different cell towers in your log.

Which provider are you connecting to?

 

Kind regards,

Håkon

[JackyChen]

I use China-Mobile SIM card which is dedicated for IOT,  their technical support said that IP and DNS are obtained at the same time.

I plug the SIM card into my phone , my phone can surf the Internet with this SIM card.

So, I'm not sure if there's a compatibility problem with the way to gets DNS?