Problem with ECM mode in RM520N-GL

IoT Modules 5G Module
1

Hello,

I am using the RM520N-GL modem and a Raspberry Pi and I am facing the following problem.

I have made PDU Profiles using the AT+CGDCONT command.

AT+CGDCONT?

+CGDCONT: 1,“IPV4V6”,“internet”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,“”,0
+CGDCONT: 2,“IPV4V6”,“ims”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,“”,0
+CGDCONT: 3,“IPV4V6”,“sos”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,1,“”,0
+CGDCONT: 4,“IPV4V6”,“internet_EMBB00000B”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,0,“01.00000B”,0
+CGDCONT: 5,“IPV4V6”,“internet_EMBB00000C”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,0,“01.00000C”,0

When I activate CID 1 I get an IP and can connect to the Internet:

AT+CGACT?

+CGACT: 1,1
+CGACT: 2,0
+CGACT: 3,0
+CGACT: 4,0
+CGACT: 5,0

AT+CGPADDR

+CGPADDR: 1,“172.16.222.212”
+CGPADDR: 2,“0.0.0.0”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”
+CGPADDR: 3,“0.0.0.0”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”
+CGPADDR: 4,“0.0.0.0”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”
+CGPADDR: 5,“0.0.0.0”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”

OK

pi@rpi:~ $ ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
From 150.140.195.193 icmp_seq=2 Packet filtered (I am using a VPN but it can reach the Network)

However, when I deactivate the CID 1 and activate another Profile:
(In order to deactivate CID 1 I add a DNN that is not available via my 5G Network because it always tries to activate CID 1)

AT+CGDCONT?

+CGDCONT: 1,“IPV4V6”,“default”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,“”,0
+CGDCONT: 2,“IPV4V6”,“ims”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,“”,0
+CGDCONT: 3,“IPV4V6”,“sos”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,1,“”,0
+CGDCONT:4,“IPV4V6”,“internet_EMBB00000B”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,0,“01.00000B”,0
+CGDCONT:5,“IPV4V6”,“internet_EMBB00000C”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,0,“01.00000C”,0

And I activate CID 4 (same DNN but with specific requested NSSAI)
AT+CGACT=1,4

OK

+CGEV: PDN ACT 4

AT+CGACT?

+CGACT: 1,0
+CGACT: 2,0
+CGACT: 3,0
+CGACT: 4,1
+CGACT: 5,0

OK

And I get an IP address
AT+CGPADDR

+CGPADDR: 1,“0.0.0.0”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”
+CGPADDR: 2,“0.0.0.0”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”
+CGPADDR: 3,“0.0.0.0”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”
+CGPADDR: 4,“172.16.222.212”
+CGPADDR: 5,“0.0.0.0”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”

OK

But when I try to ping:
pi@rpi:~ $ ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
From 192.168.225.1 icmp_seq=1 Destination Net Unreachable
From 192.168.225.1 icmp_seq=2 Destination Net Unreachable

I am using ECM mode

AT+QCFG=“usbnet”

+QCFG: “usbnet”,1

I understand that the modem exposes usb0 and via dhcp it assigns to the interface an IP and it gets one itself (192.168.225.1).

The usb0 interface is exposed:
11: usb0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
link/ether 06:60:b6:c9:34:ff brd ff:ff:ff:ff:ff:ff
inet 192.168.225.156/22 brd 192.168.227.255 scope global dynamic noprefixroute usb0
valid_lft 42837sec preferred_lft 42837sec
inet6 fe80::881c:ca0a:e8c3:b4c/64 scope link noprefixroute
valid_lft forever preferred_lft forever

and the ip route is:
pi@rpi:~ $ ip route
default via 192.168.225.1 dev usb0 proto dhcp src 192.168.225.156 metric 102

I have checked the Network Configuration and it is fine from Network’s point of view the modem has a functional IP address and I can ping the 172.16.222.212 (modem IP) from my gNB.

I also tried :
AT+QPING=4,“8.8.8.8”,1,4

OK

+QPING: 561

So whats happening? Why I cant reach the Network from my Rpi when I activate any other CID except the first?

How can I accomplish having connection to the internet when I activate any of the available profiles?

2

Dear @esake
Only ping 8.8.8.8 has issue, right?
Do you have network slice?
Please show ifconfig and route -n

3

Dear Silvia,

I changed the mode to QMI and I used quectel-CM. The problem was solved and now i have access to the network regardless which CID is activated.

I would like to use quectel-CM in order to establish multi-APN connections. For that i have requested the qmi_wwan_q driver in the forum but i dont have a response and its been a week. Is it possible to send it to me along with some instructions on how to activate it and use it with quectel-CM?

And also if it doesn’t work for me how can i change it back to qmi_wwan that i am currently using?

I am using the RM520N-GL modem with a Raspberry Pi.

Thank you !!!

4

Dear @esake
I have sent to you via Message, please check.
If don’t want to use qmi_wwan_q, you can try to uninstall it.

5

Hello @esake
Do you have access to the qmi_wwan drivers for rm520? If yes, can you share it?

Thanks in advance!!

Ps:
Email: tiagojoseas@gmail.com

6

Dear @Tiago_Sousa
I have sent to your via Message, please check.