This bug needs to be assigned an importance level.

Below is the output from the daemon log:

Nov  6 22:27:18 grn-ubuntu modem-manager: (ttyUSB0) opening serial device...
Nov  6 22:27:18 grn-ubuntu modem-manager: (ttyUSB0): probe requested by plugin 'Huawei'
Nov  6 22:27:18 grn-ubuntu modem-manager: (Huawei): (ttyUSB1) deferring support check
Nov  6 22:27:18 grn-ubuntu modem-manager: (Huawei): (ttyUSB2) deferring support check
Nov  6 22:27:19 grn-ubuntu modem-manager: (ttyUSB0) closing serial device...
Nov  6 22:27:19 grn-ubuntu modem-manager: (Huawei): CDMA modem /sys/devices/pci0000:00/0000:00:02.0/usb3/3-2 claimed port ttyUSB0
Nov  6 22:27:19 grn-ubuntu modem-manager: Added modem /sys/devices/pci0000:00/0000:00:02.0/usb3/3-2
Nov  6 22:27:19 grn-ubuntu modem-manager: Exported modem /sys/devices/pci0000:00/0000:00:02.0/usb3/3-2 as /org/freedesktop/ModemManager/Modems/3
Nov  6 22:27:19 grn-ubuntu NetworkManager: <info>  (ttyUSB0): new CDMA device (driver: 'option1')
Nov  6 22:27:19 grn-ubuntu NetworkManager: <info>  (ttyUSB0): exported as /org/freedesktop/NetworkManager/Devices/4
Nov  6 22:27:19 grn-ubuntu NetworkManager: <info>  (ttyUSB0): now managed
Nov  6 22:27:19 grn-ubuntu NetworkManager: <info>  (ttyUSB0): device state change: 1 -> 2 (reason 2)
Nov  6 22:27:19 grn-ubuntu NetworkManager: <info>  (ttyUSB0): deactivating device (reason: 2).
Nov  6 22:27:19 grn-ubuntu NetworkManager: flush_routes: assertion `iface_idx >= 0' failed
Nov  6 22:27:19 grn-ubuntu NetworkManager: flush_addresses: assertion `iface_idx >= 0' failed
Nov  6 22:27:19 grn-ubuntu NetworkManager: <info>  (ttyUSB0): device state change: 2 -> 3 (reason 0)
Nov  6 22:27:21 grn-ubuntu modem-manager: (ttyUSB1): re-checking support...
Nov  6 22:27:21 grn-ubuntu modem-manager: (ttyUSB1) opening serial device...
Nov  6 22:27:21 grn-ubuntu modem-manager: (ttyUSB1): probe requested by plugin 'Huawei'
Nov  6 22:27:21 grn-ubuntu modem-manager: (ttyUSB2): re-checking support...
Nov  6 22:27:21 grn-ubuntu modem-manager: (ttyUSB2) opening serial device...
Nov  6 22:27:22 grn-ubuntu modem-manager: (ttyUSB2): probe requested by plugin 'Huawei'
Nov  6 22:27:23 grn-ubuntu modem-manager: (ttyUSB2) closing serial device...
Nov  6 22:27:23 grn-ubuntu modem-manager: (Huawei): CDMA modem /sys/devices/pci0000:00/0000:00:02.0/usb3/3-2 claimed port ttyUSB2
Nov  6 22:27:24 grn-ubuntu wpa_supplicant[1131]: CTRL-EVENT-SCAN-RESULTS 
Nov  6 22:27:33 grn-ubuntu modem-manager: (ttyUSB1) closing serial device...
Nov  6 22:27:37 grn-ubuntu NetworkManager: <info>  Activation (ttyUSB0) starting connection 'Reliance Netconnect'
Nov  6 22:27:37 grn-ubuntu NetworkManager: <info>  (ttyUSB0): device state change: 3 -> 4 (reason 0)
Nov  6 22:27:37 grn-ubuntu NetworkManager: <info>  Activation (ttyUSB0) Stage 1 of 5 (Device Prepare) scheduled...
Nov  6 22:27:37 grn-ubuntu NetworkManager: <info>  Activation (ttyUSB0) Stage 1 of 5 (Device Prepare) started...
Nov  6 22:27:37 grn-ubuntu NetworkManager: <info>  Activation (ttyUSB0) Stage 1 of 5 (Device Prepare) complete.
Nov  6 22:27:37 grn-ubuntu modem-manager: (ttyUSB0) opening serial device...
Nov  6 22:27:37 grn-ubuntu modem-manager: (ttyUSB2) opening serial device...
Nov  6 22:28:38 grn-ubuntu NetworkManager: <WARN>  stage1_prepare_done(): CDMA modem connection failed: No service
Nov  6 22:28:38 grn-ubuntu NetworkManager: <info>  (ttyUSB0): device state change: 4 -> 9 (reason 0)
Nov  6 22:28:38 grn-ubuntu NetworkManager: <info>  Marking connection 'Reliance Netconnect' invalid.
Nov  6 22:28:38 grn-ubuntu NetworkManager: <info>  Activation (ttyUSB0) failed.
Nov  6 22:28:38 grn-ubuntu NetworkManager: <info>  (ttyUSB0): device state change: 9 -> 3 (reason 0)
Nov  6 22:28:38 grn-ubuntu NetworkManager: <info>  (ttyUSB0): deactivating device (reason: 0).
Nov  6 22:28:38 grn-ubuntu NetworkManager: flush_routes: assertion `iface_idx >= 0' failed
Nov  6 22:28:38 grn-ubuntu NetworkManager: flush_addresses: assertion `iface_idx >= 0' failed
Nov  6 22:28:38 grn-ubuntu modem-manager: (ttyUSB2) closing serial device...
Nov  6 22:28:38 grn-ubuntu modem-manager: (ttyUSB0) closing serial device...