Em12g Reset ECM internal data call

We are configuring EM12g using ECM. We have a module that will register on the network and return IP addresses back like 192.168.225.50 and gateway 192.168.225.1 but we cannot ping through to outside IP’s.

We have verified that all settings, APN, etc is correct. It seems to be a setting in the module itself as we can swap out the modem with another EM12g and it will register, return similar IP’s and we’ll be able to ping out to the outside world.

Is there a routing table of some sort or a way that we can see what internal routing is happening on the module itself in ecm (usbnet=1) mode? Is there an AT command that can force the routing to be re-built?

We have tried a AT+QPRTPARA=3 to reset the module and that did not work.

If we switch into QMI or MBIM, the modem will register and everything works fine as well. We would like to use ECM for our project.

Thanks for your help!

Hi, njwcei:
Is it the ip address “192.168.225.50” you got from “AT+CGPADDR”? This address is a private ip address, typically used on a LAN;But,the IP address you get from the module should be a public IP address.The IP address obtained by the module is provided by the network side,at the same time,there should be no address routing function inside the module.
Can you provide the process log of your operation?
Or ,Refer to the following :


I hope we can solve your problem. If the problem still exists, we will keep communicating. Thank you!

Thanks for the reply. Yes, the IP we get from the modem looks like a public, but we can’t ping through it at all. Here’s what we get:

Tue Apr 20 15:13:21 2021 : /dev/ttyUSB2 at+qiact=1
OK

Tue Apr 20 15:21:02 2021 : /dev/ttyUSB2 AT+QIACT?
+QIACT: 1,1,1,“6.78.133.68”
OK

Tue Apr 20 15:21:45 2021 : /dev/ttyUSB2 AT+QPING=1,“www.baidu.com
OK

Tue Apr 20 15:24:29 2021 : /dev/ttyUSB2 AT+QPING=1,“8.8.8.8”
OK

Here’s our process log:

ATI
Quectel
EM12
Revision: EM12GPAR01A20M4G
OK
AT+CNUM
OK
AT+CPBR=?
+CME ERROR: 100

Tue Apr 20 16:15:25 2021 : /dev/ttyUSB2 AT+CGMI
Quectel
OK

Tue Apr 20 16:15:26 2021 : /dev/ttyUSB2 AT+CGMM
EM12
OK

Tue Apr 20 16:15:27 2021 : /dev/ttyUSB2 AT+CG
+CPIN: READY
+QUSIM: 1
SN
8697100305xxxxx
OK

Tue Apr 20 16:15:28 2021 : /dev/ttyUSB2 AT+QCFG=“nw
+QIND: PB DONE
scanmode”
+QCFG: “nwscanmode”,0
OK

Tue Apr 20 16:15:29 2021 : /dev/ttyUSB2 AT+CIMI
3102605xxxxxxxx
OK

Tue Apr 20 16:15:32 2021 : /dev/ttyUSB2 AT+CRSM=176,12258,0,0,10
+CRSM: 144,0,“981062500057xxxxxxxxx”
OK

Tue Apr 20 16:15:50 2021 : /dev/ttyUSB2 AT+COPS=3,0;+COPS?
+COPS: 0,0,“T-Mobile”,7
OK
AT+COPS=3,2;+COPS?
+COPS: 0,2,“310260”,7
OK
ATI
Quectel
EM12
Revision: EM12GPAR01A20M4G
OK
AT+CGEQNEG=1
ERROR
AT+CNUM
+CNUM: ,“16xxxxxxxxxxx”,129
OK

Tue Apr 20 16:15:53 2021 : /dev/ttyUSB2 AT+CREG=2;+CREG?;+CREG=0
+CREG: 2,1,“AB02”,“07E8D16”,7
OK
AT+CEREG=2;+CEREG?;+CEREG=0
+CEREG: 2,1,“AB02”,“07E8D16”,7
OK
AT+C5GREG=2;+C5GREG?;+C5GREG=0
ERROR

Thanks!

Hi,njwcei:

Tue Apr 20 15:21:02 2021 : /dev/ttyUSB2 AT+QIACT?
+QIACT: 1,1,1,“6.78.133.68”
OK

From the above results you can see that the IP address you got from the module is“6.78.133.68”;At the same time,You PING the result below also displays “OK”,no “ERROR” .

Tue Apr 20 15:21:45 2021 : /dev/ttyUSB2 AT+QPING=1,“www.baidu.com
OK
Tue Apr 20 15:24:29 2021 : /dev/ttyUSB2 AT+QPING=1,“8.8.8.8”
OK

The other AT Command results also show no exception errors.

AT+C5GREG=2;+C5GREG?;+C5GREG=0
ERROR
This “ERROR” is because EM12G is a 4G module and does not support 5G, so if you use" AT+C5GREG ", it will not work

I don’t know how you pinged, is it IP address or domain name?
I suggest that you can do an operation check on your own computer for the IP address and domain name you PING. If it is a domain name problem, it may be related to DNS.
I suggest that you LOG back to me the result of PING execution error, and I will troubleshoot it again. I hope your problem can be solved, thank you!

Thank you for your response. The PING showed an OK, but we never got a response, and that is the same thing that happens in the operating system, it will sit on Pinging 8.8.8.8… and will never return a response.

We can do a refresh on the network interface and it always returns a private IP address from the module, but no ping or traffic will go across.

Are there any other AT commands that can be used to debug, reset, or ‘refresh’ the route between the private IP and the public one?

Now that I think about it, the problem seemed to have started when we switched a sim card without changing the APN, and we were denied registration. After we entered the new APN, it would register but we could never ping a public address.

We could use a different modem module and it would register and we can ping using ECM, but if we were ever denied registration, it would block that modem from being able to ping outside.

Is there a command to clear the memory or reset the ecm portion of the module?

Hi,njwcei:
Why would you want to refresh or reset the ECM?
If the APN of your current module configuration is incorrect, you reconfigure an APN that matches the SIM card,That’s OK in this way!

Here are the steps to reproduce this bug.

I’m starting with a fresh, never before used Quectel EM12g modem. I connect through ecm mode and when I run a traceroute from the router, this is the response:

traceroute 8.8.8.8
traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 38 byte packets

1 192.168.225.1 (192.168.225.1) 1.596 ms 1.853 ms 1.649 ms
2 10.170.226.192 (10.170.226.192) 64.706 ms 49.337 ms 48.272 ms
3 10.163.0.61 (10.163.0.61) 70.535 ms 48.601 ms 59.943 ms
4 10.164.176.101 (10.164.176.101) 51.251 ms 48.978 ms 57.945 ms
5 74.125.147.188 (74.125.147.188) 51.705 ms 53.933 ms 64.595 ms

Notice the traffic is correctly routed through the private IP of the modem, and travels correctly to the public side.

Next, I’ll insert a different sim that does not have service, or set the APN to an incorrect value so you get ‘registration denied’

AT+CGDCONT= 1,“IPV4V6”,“incorrect”

AT+CREG?
+CREG: 0,3 (DENIED)

Now I’ll re-insert the active sim that was just used and set the correct APN

AT+CGDCONT= 1,“IPV4V6”,“fast.t-mobile.com

Verify connection and registration:

AT+CREG?
+CREG: 2,1,“AB02”,“07E8D16”,7

AT+COPS?
+COPS: 0,0,“T-Mobile”,7

Verify ip addresses:
AT+CGCONTRDP
+CGCONTRDP: 1,5,fast.t-mobile.com,29.22.230.174,38.7.251.144.108.56.248.114.0.0.0.28.184.106.247.1, 254.128.0.0.0.0.0.0.0.0.0.28.184.106.247.64,10.177.0.34 253.0.151.106.0.0.0.0.0.0.0.0.0.0.0.9,10.177.0.210 253.0.151.106.0.0.0.0.0.0.0.0.0.0.0.16

at+qiact=1
AT+QIACT?
+QIACT: 1,1,1,“29.22.230.174”

When I run a ping or traceroute, there is no data connection through the modem:

traceroute 8.8.8.8

traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 38 byte packets
1 192.168.225.1 (192.168.225.1) 1.705 ms !N 1.869 ms !N * FAILED

ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8): 56 data bytes (waits… never gets a response)

ping from computer fails at modem:
PING 8.8.8.8 (8.8.8.8): 56 data bytes
92 bytes from 192.168.225.1 : Destination Net Unreachable
Vr HL TOS Len ID Flg off TTL Pro cks Src Dst
4 5 00 5400 3166 0 0000 41 01 75dc 192.168.1.175 8.8.8.8

At this point, the modem can no longer be used for an ecm (usbnet=1) connection. The modem will still work in QMI or MBIM mode, but ecm will never work again.

There has to be a way to reset the modem to allow for new connections after a denied registration. I have now lost the ability to connect ecm in 4 modems.

Hi, njwcei:
Execute the following commands in your current state:

udhcpc -i usb0

Try this and see if it can solve your problem. If the problem still exists, we will keep communicating. Thank you!

udhcpc -i usb0

We have tried this and it will renew the private IP, but it has no effect on the problem.

We have poured through countless Quectel PDF’s and forum posts trying to find an answer to this with no luck.

Hi,njwcei:
Sorry, I’m also confused about this problem. If you still can’t solve it by trying other methods, you can contact our Local-FAE, who can seek a solution from our R&D team.

Thank you, how can I get in contact with them please?

Hi,njwcei:
Do you do anything else to the ECM card, such as setting the ECM card as the default route.
If your problem still cannot be solved in the end, you can send a detailed description of your problem to email support@quectel.com,We will provide better help,thank you!

No, we don’t do anything to the module. From a new modem, it connects just fine. As soon as a network registration deny, it will never connect again. It’s like it corrupts the ecm part of the modem.

The same happen to me I have Quectel EM20G but imposible use in to ECM Mode , when I try to acces to the ip (192.168.225.1) I see a login panel but I don’t have idea how get it , in that interface we must check the configuration of ECM , because the rest of the configuration It was working correctly.

at+qcfg=“usbnet”,1
then reboot the module.
udhcpc -n -q -f -i usb0 //get ip
ifconfig -a //check to see if usb0 get ip
route -n //check to see if iptable is correct
If usb0 is not in the iptable. Look for default.script with “udhcpc --help”.
Modify default.script as below: add " route add $i dev $interface " between “for i in $router ; do” and " route add default gw $i dev $interface". Then reboot it.

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This does not help unfortunately. This code assumes the router itself has lost the route, but it remains. In a qualcomm site (can’t remember where I saw it), it talks about the modem having an internal ‘router’ in ECM mode. That’s why it gives a private IP of 192.168.225.x and routes out to the public. This internal ‘router’ is where the problem lies.

I have a RM502q-ae and I can see the ‘router’ settings when I go to https://192.168.225.1 - nothing works as the jquery include is missing, but there are settings there.

There HAS to be a command that can either reset or refresh the internal ‘router’ settings on this modem. Any ideas? I have reached out to support@quectel and have not received a reply.

Thanks

Can anyone at Quectel ping someone that might be able to shed some light on this?

Okay,i will check for myself.

I just check it myself on my ubuntu computer. ECM data call. My computer got a private IP of 192.168.225.1. Ping 8.8.8.8 is OK. My module’s firmware is EM12GPAR01A20M4G. Maybe you can try to upgrade your EM12G’s firmware. I’m sorry that I have no permission to upload pictures, because I’m a new user.