> sudo systemctl status ModemManager.service 
root's password:
ModemManager.service - Modem Manager
   Loaded: loaded (/usr/lib/systemd/system/ModemManager.service; enabled)
   Active: active (running) since Fr 2016-02-26 13:51:09 CET; 6min ago
 Main PID: 775 (ModemManager)
   CGroup: /system.slice/ModemManager.service                                                                                                                                                                                                                                  
           └─775 /usr/sbin/ModemManager                                                                                                                                                                                                                                        
                                                                                                                                                                                                                                                                               
Feb 26 13:51:08 linux-pezc ModemManager[775]: <info>  ModemManager (version 1.4.10) starting in system bus...                                                                                                                                                                  
Feb 26 13:51:09 linux-pezc ModemManager[775]: <warn>  (ttyUSB0): port attributes not fully set                                                                                                                                                                                 
Feb 26 13:51:09 linux-pezc ModemManager[775]: <warn>  (ttyUSB1): port attributes not fully set                                                                                                                                                                                 
Feb 26 13:51:11 linux-pezc ModemManager[775]: <info>  Couldn't find support for device at '/sys/devices/pci0000:00/0000:00:03.0': not supported by any plugin                                                                                                                  
Feb 26 13:51:12 linux-pezc ModemManager[775]: <warn>  (ttyUSB1): port attributes not fully set                                                                                                                                                                                 
Feb 26 13:51:28 linux-pezc ModemManager[775]: <info>  Creating modem with plugin 'Huawei' and '4' ports                                                                                                                                                                        
Feb 26 13:51:28 linux-pezc ModemManager[775]: <warn>  Could not grab port (tty/ttyUSB1): 'Cannot add port 'tty/ttyUSB1', unhandled serial type'                                                                                                                                
Feb 26 13:51:28 linux-pezc ModemManager[775]: <warn>  (ttyUSB0): port attributes not fully set                                                                                                                                                                                 
Feb 26 13:51:28 linux-pezc ModemManager[775]: <info>  Modem for device at '/sys/devices/pci0000:00/0000:00:0b.0/usb1/1-1' successfully created                                                                                                                                 
Feb 26 13:51:54 linux-pezc ModemManager[775]: <warn>  Modem couldn't be initialized: couldn't load current capabilities: Failed to determine modem capabilities.