ppp connection lost after ~20 minutes
Hello, we have an imx6 based hardware with an 4.19.35 kernel, NtworkManager v1.40.0 and ModemManager v1.18.12. Our modem is a Quectel EG91 (EG91EXGAR08A04M1G), the networkmanager connection is attached: my_connection.nmconnection
When the system starts, we have internet access, and can ping servers, everything seems fine. After some random time, for instance 20 minutes, we lose the network connection and can't ping any more, details can be seen in the attached syslog: 20230123_syslog_2.dat. I think starting at line 4694 is of intereset:
Jan 23 10:04:29 scu ModemManager[300]: <debug> [1674468269.416915] [modem0/ttyUSB3/at] <-- '<CR><LF>+CIND: 0,0,0,0,0,0,0,2<CR><LF><CR><LF>OK<CR><LF>'
The EG91 reports, that it has lost connection to the network. ModemManager still reports the bearer as connected:
root@scu:~# mmcli r -m 0
--------------------------------
General | path: /org/freedesktop/ModemManager1/Modem/0
| device id: e758cc2ca45d873c11d0233edfa4358b77fcd9e5
--------------------------------
Hardware | manufacturer: Quectel
| model: EG91
| firmware revision: EG91EXGAR08A04M1G
| supported: gsm-umts, lte
| current: gsm-umts, lte
| equipment id: 867648041122944
--------------------------------
System | device: /sys/devices/soc0/soc/2100000.aips-bus/2184200.usb/ci_hdrc.0/usb1/1-1
| drivers: option
| plugin: quectel
| primary port: ttyUSB2
| ports: ttyUSB0 (qcdm), ttyUSB1 (gps), ttyUSB2 (at), ttyUSB3 (at)
--------------------------------
Status | unlock retries: sim-pin (3), sim-pin2 (3), sim-puk (10), sim-puk2 (10)
| state: connected
| power state: on
| access tech: lte
| signal quality: 0% (recent)
--------------------------------
Modes | supported: allowed: 2g, 3g, 4g; preferred: none
| current: allowed: 2g, 3g, 4g; preferred: none
--------------------------------
IP | supported: ipv4, ipv6, ipv4v6
--------------------------------
3GPP | imei: 867648041122944
| operator id: 26202
| operator name: vodafone.de
| registration: roaming
--------------------------------
3GPP EPS | ue mode of operation: csps-2
--------------------------------
SIM | primary sim path: /org/freedesktop/ModemManager1/SIM/0
--------------------------------
Bearer | paths: /org/freedesktop/ModemManager1/Bearer/0
Networkmanager also still reports the device (ttyUSB2) as connected:
root@scu:~# nmcli device
DEVICE TYPE STATE CONNECTION
ttyUSB2 gsm connected my connection
eth0 ethernet connected (externally) eth0
ppp0 ppp disconnected --
can0 can unmanaged --
can1 can unmanaged --
can2 can unmanaged --
sit0 iptunnel unmanaged --
lo loopback unmanaged --
Please also note that ppp0 is shown as disconnected, which is always the case in our scenario, even when the connection works.
Best regards,
Markus