Telit 5G modem - how to pump data when connected to linux machine

Cellular Modules
1

Telit FN980m cellular module. connected to Ubuntu OS over USB.

I can read AT command responses on one of the ttyUSB interfaces, ttyUSB4.

Can someone please guide how to pump data using a linux machine? I tried below AT commands but “ifconfig” does not list any new ip address for the connected Telit modem.

at+cgdcont?
+CGDCONT: 1,“IPV4V6”,"",“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”,"",“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,"",0
OK

AT+CGPADDR=1
+CGPADDR: 1,100.193.76.181,38.7.251.144.130.53.201.20.0.0.0.34.96.26.99.1
OK

AT+CGPADDR=2
+CGPADDR: 2,38.7.252.32.130.81.89.167.0.0.0.51.246.141.51.1
OK

at#usbcfg?
#USBCFG: 1
OK

AT#ICMCONNECT?
#ICMCONNECT: 1,1,0,1,0
OK

AT#ICMCONNECT=con,1,4
OK

AT#ICMCONNECT=con,1,6
OK

AT#ICMCONNECT?
#ICMCONNECT: 1,1,1,1,1
OK

AT+CGPADDR=1
+CGPADDR: 1,100.193.76.181,38.7.251.144.130.53.201.20.0.0.0.34.96.26.99.1
OK

2

Above steps worked on Windows machine after changing USBCFG to RNDIS interface. Host PC could connect to internet over Telit modem via tethering.

How can I achieve it on Linux machine? After changing USBCFG for RNDIS interface, I’m unable to issue/ read AT commands via modem port.

3

Hey @gaurish, I don’t have a FN980 (only LM960) but try this guide from Techship which seems to be about what you want to do:

Let me know if that worked for you!

1 Like
4

Many thanks for your response. It was a good lead. I also reached out to Telit support and received another lead. I’m able to connect to internet through the USB connected Telit FN980 module from my Linux Host PC.

USBCFG is set to 1 for RmNET interface.

Module attaches to the network using AT commands.

On the Linux host PC, I created a network connection using nmcli command. I could see modem IP (which is printed for +CGPADDR=1) getting listed under ifconfig on the host PC.

$dmesg -w
. .
[ 4506.016855] usb 1-1.2: Product: FN980m
[ 4506.016858] usb 1-1.2: Manufacturer: Telit Wireless Solutions
[ 4506.016861] usb 1-1.2: SerialNumber: a5095cf6
[ 4506.019482] option 1-1.2:1.0: GSM modem (1-port) converter detected
[ 4506.019669] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB0
[ 4506.023582] qmi_wwan 1-1.2:1.2: cdc-wdm1: USB WDM device
[ 4506.024283] qmi_wwan 1-1.2:1.2 wwan0: register ‘qmi_wwan’ at usb-0000:00:1a.0-1.2, WWAN/QMI device, ba:ed:20:bf:99:c6

Linux command to create a new interface for the Telit modem
$ nmcli connection add type gsm ifname ‘cdc-wdm1’ con-name ‘telitnet’
Connection ‘telitnet’ (f1fe1592-e336-4a83-81f1-2ebc44ed5331) successfully added.

Routing Table on the host PC shows modem IP address
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 6.245.108.197 0.0.0.0 UG 700 0 0 wwan0
6.245.108.192 0.0.0.0 255.255.255.248 U 700 0 0 wwan0