我有一个非常有趣的问题：我正尝试使用调制解调器 (Telit LE910C4-EU) 在 RPi4 上实现蜂窝连接。为此，我使用调制解调器管理器和网络管理器：
apt-get update
apt-get install network-manager
apt-get install modemmanager
reboot
mmcli -m 0 --simple-connect="apn=sphone"
nmcli c add type gsm ifname ttyACM0 con-name cellcom apn sphone
nmcli con up id cellcom
这在 Ubuntu 服务器（最新 20.04）上完美运行，并且我获得了互联网连接。另一方面，在 Raspbian OS（最新稳定版本 2020-05-27）上，使用相同的 Pi、调制解调器和 SIM 卡 - 这不起作用！
经过调查，我注意到 Ubuntu 上的 wwan0 接口由网络管理器创建为 POINTTOPOINT 接口，而在 Raspbian 上，则创建为普通的以太网接口！有人知道为什么会发生这种情况，以及我们如何改变它吗？
Raspbian-ifconfig：
eth0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether dc:a6:32:b1:5a:5e txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 259 bytes 23782 (23.2 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 259 bytes 23782 (23.2 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
wlan0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether b2:05:a3:5a:38:da txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
wwan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.129.78.129 netmask 255.255.255.252 broadcast 10.129.78.131
inet6 2001:4df7:0:9e68:419:3bba:8e96:a9e1 prefixlen 64 scopeid 0x0<global>
ether 8a:36:72:11:0c:17 txqueuelen 1000 (Ethernet)
RX packets 15 bytes 1116 (1.0 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 264 bytes 18003 (17.5 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
Ubuntu-ifconfig：
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.100.102.21 netmask 255.255.255.0 broadcast 10.100.102.255
inet6 fe80::dea6:32ff:feb1:5a5e prefixlen 64 scopeid 0x20<link>
ether dc:a6:32:b1:5a:5e txqueuelen 1000 (Ethernet)
RX packets 877 bytes 96168 (96.1 KB)
RX errors 0 dropped 514 overruns 0 frame 0
TX packets 273 bytes 43483 (43.4 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 100 bytes 7644 (7.6 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 100 bytes 7644 (7.6 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
wlan0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether dc:a6:32:b1:5a:5f txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
wwan0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500
inet 10.153.125.200 netmask 255.255.255.240 destination 10.153.125.200
inet6 2a02:14f:1ff:a8ed:618f:e5f2:eb86:9265 prefixlen 64 scopeid 0x0<global>
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 1000 (UNSPEC)
RX packets 8 bytes 850 (850.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 5 bytes 480 (480.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
Raspbian-mmcli-m 0：
--------------------------------
General | dbus path: /org/freedesktop/ModemManager1/Modem/0
| device id: 4f1ed10242afd5fc1f738ab4dafd23f27ec81eea
--------------------------------
Hardware | manufacturer: QUALCOMM INCORPORATED
| model: LE910C4-EU
| revision: 25.20.673 1 [Dec 11 2018 23:00:00]
| h/w revision: 10000
| supported: gsm-umts, lte
| current: gsm-umts, lte
| equipment id: XXXXXXXXXXXXXXXXXXX
--------------------------------
System | device: /sys/devices/platform/scb/fd500000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0/usb1/1-1/1-1.2
| drivers: option1, qmi_wwan
| plugin: Telit
| primary port: cdc-wdm0
| ports: ttyUSB2 (at), cdc-wdm0 (qmi), wwan0 (net), ttyUSB3 (at)
--------------------------------
Status | lock: sim-pin2
| unlock retries: sim-pin (5), sim-pin2 (5), sim-puk (5), sim-puk2 (5)
| state: connected
| power state: on
| access tech: lte
| signal quality: 100% (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, utran-1, utran-3, utran-8, eutran-1, eutran-3,
| eutran-7, eutran-8, eutran-20, eutran-28
| current: egsm, dcs, utran-1, utran-3, utran-8, eutran-1, eutran-3,
| eutran-7, eutran-8, eutran-20, eutran-28
--------------------------------
IP | supported: ipv4, ipv6, ipv4v6
--------------------------------
3GPP | imei: XXXXXXXXXXXXXXXXXXXX
| operator id: 42502
| operator name: Cellcom
| registration: home
--------------------------------
3GPP EPS | ue mode of operation: csps-1
--------------------------------
SIM | dbus path: /org/freedesktop/ModemManager1/SIM/0
--------------------------------
Bearer | dbus path: /org/freedesktop/ModemManager1/Bearer/2
Ubuntu-mmcli-m 0：
--------------------------------
General | dbus path: /org/freedesktop/ModemManager1/Modem/0
| device id: 4f1ed10242afd5fc1f738ab4dafd23f27ec81eea
--------------------------------
Hardware | manufacturer: QUALCOMM INCORPORATED
| model: LE910C4-EU
| firmware revision: 25.20.673 1 [Dec 11 2018 23:00:00]
| carrier config: default
| h/w revision: 10000
| supported: gsm-umts, lte
| current: gsm-umts, lte
| equipment id: XXXXXXXXXXXXXXXXXX
--------------------------------
System | device: /sys/devices/platform/scb/fd500000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0/usb1/1-1/1-1.2
| drivers: option1, qmi_wwan
| plugin: Telit
| primary port: cdc-wdm0
| ports: cdc-wdm0 (qmi), ttyUSB2 (at), wwan0 (net), ttyUSB3 (at)
--------------------------------
Status | lock: sim-pin2
| unlock retries: sim-pin (5), sim-puk (5), sim-pin2 (5), sim-puk2 (5)
| state: connected
| power state: on
| access tech: lte
| signal quality: 100% (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, utran-1, utran-3, utran-8, eutran-1, eutran-3,
| eutran-7, eutran-8, eutran-20, eutran-28
| current: egsm, dcs, utran-1, utran-3, utran-8, eutran-1, eutran-3,
| eutran-7, eutran-8, eutran-20, eutran-28
--------------------------------
IP | supported: ipv4, ipv6, ipv4v6
--------------------------------
3GPP | imei: XXXXXXXXXXXXXXXXXX
| operator id: 42502
| operator name: Cellcom
| registration: home
--------------------------------
3GPP EPS | ue mode of operation: csps-1
--------------------------------
SIM | dbus path: /org/freedesktop/ModemManager1/SIM/0
--------------------------------
Bearer | dbus path: /org/freedesktop/ModemManager1/Bearer/0
有谁知道为什么会出现不同的行为，以及如何在 Raspbian 上修复它？
多谢！
维塔利