EG915N ECM NO CARRIER on Net interface

Technical Subjects
1

Hello, i am facing issues on Modem EG915N.

I configured ECM using

AT+QCFG=“usbnet”,1

On first EG915N Boot i succesfully get wwan0 interface.
Ip is successfully configured :

3: wwan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel qlen 1000
    link/ether ae:0c:29:a3:9b:6d brd ff:ff:ff:ff:ff:ff
    inet 192.168.43.100/24 brd 192.168.43.255 scope global dynamic noprefixroute wwan0
       valid_lft 86392sec preferred_lft 75592sec
    inet6 fe80::d10:67be:7f5b:1c35/64 scope link 
       valid_lft forever preferred_lft forever
    inet6 fe80::e60f:493e:59a1:d81d/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

When i reboot modem using POWERKEY :

4: wwan0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel qlen 1000
    link/ether ae:0c:29:a3:9b:6d brd ff:ff:ff:ff:ff:ff

I tried :

ip link set wwan0 down
ip link set wwan0 up

Still no IP

I tried :

busybox udhcpc -fnq -i wwan0
udhcpc: started, v1.36.1
Dropped protocol specifier '.udhcpc' from 'wwan0.udhcpc'. Using 'wwan0' (ifindex=4).
udhcpc: broadcasting discover
udhcpc: broadcasting discover
udhcpc: broadcasting discover
udhcpc: no lease, failing

Still no IP

I tried using both complete manual AT sequence based on “EC200S Linux USB
Driver User Guide” and ModemManager Quecel ECM version (https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/merge_requests/1277)

I am using configuration below :
model: EG915N
firmware revision: EG915NEUAGR03A08M16

Thanks in advance for the help :slight_smile:

2

Need to send the AT command

AT+QNETDEVCTL=1,1,1

3

Hello , thank you for answering.

I did not go into detail but i used following commands :

at+cpin?
+CPIN: READY
OK
at+csq
+CSQ: 15,99
OK
at+qicsgp=1,1,"objcobytel.com"
OK
at+cops?
+COPS: 0,0,"BOUYGTEL",7
OK
at+qiact=1
OK
at+qnetdevctl=1,1,1
OK

before and after reboot using powerkey.

Works well before but not after.

4

After you have enter the AT+QNETDEVCTL=1,1,1, make sure that it abtain the IP address.

AT+QNETDEVCTL?
AT+CGPADDR

Please check it also.
Quectel_EC200S_Linux_USB_Driver_User_Guide_V1.0.pdf (785.5 KB)

5

Concerning “EC200S Linux USB Driver User Guide”, i followed those steps. But still not having robust network interface conenction :frowning:

+CPIN: READY
+QUSIM: 1
+QNETDEVSTATUS: 1
+QIND: SMS DONE
+QIND: PB DONE
AT+CSQ
+CSQ: 23,99
OK
AT+QICSGP=1,1,"objcobytel.com"
OK
AT+COPS?
+COPS: 0,2,"20820",7
OK
AT+QIACT=1
OK
AT
AT+QNETDEVCTL?
+QNETDEVCTL: 3,1,1,1
OK
AT+CGPADDR
+CGPADDR: 1,"10.48.130.209"
+CGPADDR: 8,"2A04:CEC0:11E:AB88:0:51:F47C:BA01"
OK

ip a
3: wwan0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel qlen 1000
    link/ether ae:0c:29:a3:9b:6d brd ff:ff:ff:ff:ff:ff

busybox busybox udhcpc -fnq -i wwan0
udhcpc: started, v1.36.1
Dropped protocol specifier '.udhcpc' from 'wwan0.udhcpc'. Using 'wwan0' (ifindex=3).
udhcpc: broadcasting discover
udhcpc: broadcasting discover
udhcpc: broadcasting discover
/usr/share/udhcpc/default.script: Lease failed: 
udhcpc: no lease, failing
6

So it occurs if you just restart the Linux host.
Actually the EG915N didn’t restart. It also need a restart.