We have an existing IoT platform that was previously using the Sierra Wireless MC7455. We are looking at switching to the EG21 and hoping that it is mostly a drop-in replacement. We’re using the same IoT SIM which has previously been demonstrated to work well in multiple countries in several continents. The only thing we’re changing here (so far) is the LTE module which, in this case, is an EG21.
It looks like the module does achieve a registration with the network, but ModemManager indicates the ‘state’ stays ‘registered’.
root@0004f31dbf77:~# mmcli -m 0
--------------------------------
General | dbus path: /org/freedesktop/ModemManager1/Modem/0
| device id: 39c06785d5d506a40d1ddaa901292b089700ed81
--------------------------------
Hardware | manufacturer: QUALCOMM INCORPORATED
| model: QUECTEL Mobile Broadband Module
| firmware revision: EG21GGBR07A11M1G
| h/w revision: 10000
| supported: gsm-umts, lte
| current: gsm-umts, lte
| equipment id: [redacted]
--------------------------------
System | device: /sys/devices/soc0/soc/2100000.aips-bus/2184200.usb/ci_hdrc.1/usb1/1-1/1-1.3
| drivers: option1, qmi_wwan
| plugin: Quectel
| primary port: cdc-wdm0
| ports: ttyUSB0 (qcdm), ttyUSB2 (at), cdc-wdm0 (qmi), wwan0 (net),
| ttyUSB3 (at)
--------------------------------
Numbers | own: 15[redacted]
--------------------------------
Status | lock: sim-pin2
| unlock retries: sim-pin (3), sim-pin2 (10), sim-puk (10), sim-puk2 (10)
| state: registered
| power state: on
| access tech: lte
| signal quality: 47% (recent)
--------------------------------
Modes | supported: allowed: 2g; preferred: none
| allowed: 3g; preferred: none
| allowed: 4g; preferred: none
| allowed: 2g, 3g; preferred: 3g
| allowed: 2g, 3g; preferred: 2g
| allowed: 2g, 4g; preferred: 4g
| allowed: 2g, 4g; preferred: 2g
| allowed: 3g, 4g; preferred: 3g
| allowed: 3g, 4g; preferred: 4g
| allowed: 2g, 3g, 4g; preferred: 4g
| allowed: 2g, 3g, 4g; preferred: 3g
| allowed: 2g, 3g, 4g; preferred: 2g
| current: allowed: 2g, 3g, 4g; preferred: 4g
--------------------------------
Bands | supported: egsm, dcs, pcs, g850, utran-1, utran-4, utran-6, utran-5,
| utran-8, utran-2, eutran-1, eutran-2, eutran-3, eutran-4, eutran-5,
| eutran-7, eutran-8, eutran-12, eutran-13, eutran-18, eutran-19,
| eutran-20, eutran-25, eutran-26, eutran-28, eutran-38, eutran-39,
| eutran-40, eutran-41, utran-19
| current: egsm, dcs, pcs, g850, utran-1, utran-4, utran-6, utran-5,
| utran-8, utran-2, eutran-1, eutran-2, eutran-3, eutran-4, eutran-5,
| eutran-7, eutran-8, eutran-12, eutran-13, eutran-18, eutran-19,
| eutran-20, eutran-25, eutran-26, eutran-28, eutran-38, eutran-39,
| eutran-40, eutran-41, utran-19
--------------------------------
IP | supported: ipv4, ipv6, ipv4v6
--------------------------------
3GPP | imei: [redacted]
| operator id: 302220
| registration: home
--------------------------------
3GPP EPS | ue mode of operation: csps-2
--------------------------------
SIM | dbus path: /org/freedesktop/ModemManager1/SIM/0
--------------------------------
Bearer | dbus path: /org/freedesktop/ModemManager1/Bearer/35
The bearer number continues to increase over time.
NetworkManager shows the cdc-wdm0 connection as ‘disconnected’ but ‘available’.
root@0004f31dbf77:~# nmcli
eth1: connected to eth1
"eth1"
ethernet (fec), 00:04:F3:1D:BF:77, hw, mtu 1500
ip4 default
inet4 172.16.1.54/24
route4 0.0.0.0/0
route4 172.16.1.0/24
inet6 fe80::204:f3ff:fe1d:bf77/64
route6 ff00::/8
route6 fe80::/64
cdc-wdm0: disconnected
"cdc-wdm0"
1 connection available
gsm (option1, qmi_wwan), hw
wlan0: disconnected
"Atheros Wi-Fi"
wifi (ar6k_wlan), 00:04:F3:1D:BF:79, hw, mtu 1500
eth0: unavailable
"eth0"
ethernet (fec), 00:04:F3:1D:BF:78, hw, mtu 1500
can0: unmanaged
"can0"
can (flexcan), hw, mtu 16
can1: unmanaged
"can1"
can (flexcan), hw, mtu 16
sit0: unmanaged
"sit0"
iptunnel (sit), sw, mtu 1480
lo: unmanaged
"lo"
loopback (unknown), 00:00:00:00:00:00, sw, mtu 65536
DNS configuration:
servers: 172.16.1.10 8.8.8.8
domains: [redacted]
interface: eth1
Use "nmcli device show" to get complete information about known devices and
"nmcli connection show" to get an overview on active connection profiles.
Consult nmcli(1) and nmcli-examples(5) manual pages for complete usage details.
Reviewing profiles, the first profile APN is empty:
root@0004f31dbf77:~# qmicli -d /dev/cdc-wdm0 -p --wds-get-profile-list=3gpp
Profile list retrieved:
[1] 3gpp -
APN: ''
PDP type: 'ipv4-or-ipv6'
PDP context number: '1'
Username: ''
Password: ''
Auth: 'none'
No roaming: 'no'
APN disabled: 'no'
[2] 3gpp -
APN: 'ims'
PDP type: 'ipv4-or-ipv6'
PDP context number: '2'
Username: ''
Password: ''
Auth: 'none'
No roaming: 'no'
APN disabled: 'no'
[3] 3gpp -
APN: 'sos'
PDP type: 'ipv4-or-ipv6'
PDP context number: '3'
Username: ''
Password: ''
Auth: 'none'
No roaming: 'no'
APN disabled: 'no'
[4] 3gpp -
APN: 'tmus'
PDP type: 'ipv4-or-ipv6'
PDP context number: '4'
Username: ''
Password: ''
Auth: 'none'
No roaming: 'no'
APN disabled: 'no'
We do have the correct APN in our system connections file:
root@0004f31dbf77:/etc/NetworkManager/system-connections# cat nm.cellular
#Default Cellular Connection Options
[connection]
id=cellular
type=gsm
[gsm]
apn=super
number=*99#
[ppp]
lcp-echo-failure=3
lcp-echo-interval=5
[ipv6]
method=auto
[ipv4]
method=auto
It looks like we’re most of the way there, but we’d like to determine why we don’t see a connection established even though we get a registration on a ‘home’ network. Hopefully this is enough information to go on.