root@armadillo:~# nmcli connection add type gsm ifname ttyUSB2 apn sakura
Connection 'gsm-ttyUSB2' (a4ed3734-44e7-4586-922d-1f3bb38e0e5e) successfully added.
root@armadillo:~# nmcli connection down gsm-ttyUSB2
Connection 'gsm-ttyUSB2' successfully deactivated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/1)
root@armadillo:~# nmcli connection modify gsm-ttyUSB2 gsm.sim-operator-id 44020
root@armadillo:~# nmcli connection up gsm-ttyUSB2
Error: Connection activation failed: Connection 'gsm-ttyUSB2' is not available on the device ttyUSB2 at this time.
root@armadillo:~# nmcli connection show gsm-random: crng init done
random: 6 urandom warning(s) missed due to ratelimiting
ttyUSB2
connection.id:                          gsm-ttyUSB2
connection.uuid:                        a4ed3734-44e7-4586-922d-1f3bb38e0e5e
connection.stable-id:                   --
connection.interface-name:              ttyUSB2
connection.type:                        gsm
connection.autoconnect:                 yes
connection.autoconnect-priority:        0
connection.autoconnect-retries:         -1 (default)
connection.timestamp:                   0
connection.read-only:                   no
connection.permissions:
connection.zone:                        --
connection.master:                      --
connection.slave-type:                  --
connection.autoconnect-slaves:          -1 (default)
connection.secondaries:
connection.gateway-ping-timeout:        0
connection.metered:                     unknown
connection.lldp:                        -1 (default)
ipv4.method:                            auto
ipv4.dns:
ipv4.dns-search:
ipv4.dns-options:                       (default)
ipv4.dns-priority:                      0
ipv4.addresses:
ipv4.gateway:                           --
ipv4.routes:
ipv4.route-metric:                      -1
ipv4.ignore-auto-routes:                no
ipv4.ignore-auto-dns:                   no
ipv4.dhcp-client-id:                    --
ipv4.dhcp-timeout:                      0
ipv4.dhcp-send-hostname:                yes
ipv4.dhcp-hostname:                     --
ipv4.dhcp-fqdn:                         --
ipv4.never-default:                     no
ipv4.may-fail:                          yes
ipv4.dad-timeout:                       -1 (default)
ipv6.method:                            auto
ipv6.dns:
ipv6.dns-search:
ipv6.dns-options:                       (default)
ipv6.dns-priority:                      0
ipv6.addresses:
ipv6.gateway:                           --
ipv6.routes:
ipv6.route-metric:                      -1
ipv6.ignore-auto-routes:                no
ipv6.ignore-auto-dns:                   no
ipv6.never-default:                     no
ipv6.may-fail:                          yes
ipv6.ip6-privacy:                       -1 (unknown)
ipv6.addr-gen-mode:                     stable-privacy
ipv6.dhcp-send-hostname:                yes
ipv6.dhcp-hostname:                     --
ipv6.token:                             --
gsm.number:                             *99#
gsm.username:                           --
gsm.password:                           <hidden>
gsm.password-flags:                     0 (none)
gsm.apn:                                sakura
gsm.network-id:                         --
gsm.pin:                                <hidden>
gsm.pin-flags:                          0 (none)
gsm.home-only:                          no
gsm.device-id:                          --
gsm.sim-id:                             --
gsm.sim-operator-id:                    44020
proxy.method:                           none
proxy.browser-only:                     no
proxy.pac-url:                          --
proxy.pac-script:                       --
GENERAL.NAME:                           gsm-ttyUSB2
GENERAL.UUID:                           a4ed3734-44e7-4586-922d-1f3bb38e0e5e
GENERAL.DEVICES:                        ttyUSB2
GENERAL.STATE:                          activating
GENERAL.DEFAULT:                        no
GENERAL.DEFAULT6:                       no
GENERAL.VPN:                            no
GENERAL.ZONE:                           --
GENERAL.DBUS-PATH:                      /org/freedesktop/NetworkManager/ActiveConnection/2
GENERAL.CON-PATH:                       /org/freedesktop/NetworkManager/Settings/2
GENERAL.SPEC-OBJECT:                    --
GENERAL.MASTER-PATH: