modem stopped from being detected

Question

I am using Ubuntu 14.04 LTS and installed xubuntu-desktop environment. I removed unity by sudo apt-get purge unity ubuntu-desktop. All workings fine on Xubuntu.

Today when I visited this where there is (old unity/gnome) package-removal command listed in Cleanup section (which you can see this from web page).

And I run following command to remove/cleanup them:

sudo apt-get remove nautilus gnome-power-manager gnome-screensaver gnome-termina* gnome-pane* gnome-applet* gnome-bluetooth gnome-desktop* gnome-sessio* gnome-user* gnome-shell-common compiz compiz* unity unity* hud zeitgeist zeitgeist* python-zeitgeist libzeitgeist* activity-log-manager-common gnome-control-center gnome-screenshot overlay-scrollba*

Now on Xubuntu my modem is no longer to be detected! probably because of above removal!?

Earlier (when wireless networking through modem is working fine) nmcli device list is below (here you can see that HUWEI modem is detected at ttyUSB2):

$ nmcli dev list
GENERAL.DEVICE:                         ttyUSB2
GENERAL.TYPE:                           gsm
GENERAL.VENDOR:                         HUAWEI Technology
GENERAL.PRODUCT:                        HUAWEI Mobile
GENERAL.DRIVER:                         option1, cdc_ether
GENERAL.DRIVER-VERSION:                 
GENERAL.FIRMWARE-VERSION:               
GENERAL.HWADDR:                         (unknown)
GENERAL.STATE:                          100 (connected)
GENERAL.REASON:                         0 (No reason given)
GENERAL.UDI:                            /org/freedesktop/ModemManager1/Modem/0
GENERAL.IP-IFACE:                       ppp0
GENERAL.NM-MANAGED:                     yes
GENERAL.AUTOCONNECT:                    yes
GENERAL.FIRMWARE-MISSING:               no
GENERAL.CONNECTION:                     /org/freedesktop/NetworkManager/ActiveConnection/0
CAPABILITIES.CARRIER-DETECT:            no
CAPABILITIES.SPEED:                     unknown
CONNECTIONS.AVAILABLE-CONNECTION-PATHS: /org/freedesktop/NetworkManager/Settings/{1}
CONNECTIONS.AVAILABLE-CONNECTIONS[1]:   f7a5bf92-6bca-4f0e-a55d-cdd6ba8e5ffa | BSNL/CellOne New GPRS/3G
IP4.ADDRESS[1]:                         ip = 117.233.116.207/32, gw = 10.64.64.64
IP4.DNS[1]:                             218.248.255.161
IP4.DNS[2]:                             218.248.255.162
GENERAL.DEVICE:                         eth0
GENERAL.TYPE:                           802-3-ethernet
GENERAL.VENDOR:                         Realtek Semiconductor Co., Ltd.
GENERAL.PRODUCT:                        RTL8111/8168 PCI Express Gigabit Ethernet controller
GENERAL.DRIVER:                         r8169
GENERAL.DRIVER-VERSION:                 2.3LK-NAPI
GENERAL.FIRMWARE-VERSION:               
GENERAL.HWADDR:                         00:1C:C0:B9:3C:96
GENERAL.STATE:                          20 (unavailable)
GENERAL.REASON:                         2 (Device is now managed)
GENERAL.UDI:                            /sys/devices/pci0000:00/0000:00:1c.1/0000:02:00.0/net/eth0
GENERAL.IP-IFACE:                       
GENERAL.NM-MANAGED:                     yes
GENERAL.AUTOCONNECT:                    yes
GENERAL.FIRMWARE-MISSING:               no
GENERAL.CONNECTION:                     not connected
CAPABILITIES.CARRIER-DETECT:            yes
CAPABILITIES.SPEED:                     unknown
CONNECTIONS.AVAILABLE-CONNECTION-PATHS: 
WIRED-PROPERTIES.CARRIER:               off

And I can connect from nm-applet.

But now you can see there is no detection of modem by Network Manager though modem is plugged in:

$ lsusb
Bus 001 Device 004: ID 12d1:1436 Huawei Technologies Co., Ltd. E173 3G Modem (modem-mode)
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 002: ID 093a:2510 Pixart Imaging, Inc. Optical Mouse
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

$ nmcli dev list
GENERAL.DEVICE:                         eth0
GENERAL.TYPE:                           802-3-ethernet
GENERAL.VENDOR:                         Realtek Semiconductor Co., Ltd.
GENERAL.PRODUCT:                        RTL8111/8168 PCI Express Gigabit Ethernet controller
GENERAL.DRIVER:                         r8169
GENERAL.DRIVER-VERSION:                 2.3LK-NAPI
GENERAL.FIRMWARE-VERSION:               
GENERAL.HWADDR:                         00:1C:C0:B9:3C:96
GENERAL.STATE:                          20 (unavailable)
GENERAL.REASON:                         2 (Device is now managed)
GENERAL.UDI:                            /sys/devices/pci0000:00/0000:00:1c.1/0000:02:00.0/net/eth0
GENERAL.IP-IFACE:                       
GENERAL.NM-MANAGED:                     yes
GENERAL.AUTOCONNECT:                    yes
GENERAL.FIRMWARE-MISSING:               no
GENERAL.CONNECTION:                     not connected
CAPABILITIES.CARRIER-DETECT:            yes
CAPABILITIES.SPEED:                     unknown
CONNECTIONS.AVAILABLE-CONNECTION-PATHS: 
WIRED-PROPERTIES.CARRIER:               off

As shown above there is Bus 001 Device 004: ID 12d1:1436 Huawei Technologies Co., Ltd. E173 3G Modem (modem-mode) plugged in but no modem device available/detected by network-manager in nmcli dev list.

Thus I am now unable to connect Internet through wireless modem because modem is not deleted in nm-applet (Neither such option like "New Mobile broadband" available).

How do I solve this problem?

Answer 1

Today When I tried to restart modemmanager, I got following error:

$ sudo restart modemmanager 
restart: Unknown instance:

Also there seems some problem with modemmanager (because wired connection working fine) so I decided to re-install modemmanager

Run following command to re-install:

sudo apt-get install --reinstall network-manager modemmanager

Now modem is detected and "New Mobile Boradband Connection" is available in nm-applet (also displayed/connected in nmcli dev list). Modem is working fine.

Answer 2

1. At first click on the networking icon on the top right side of the screen
2. Then click on the edit connection button
3. Then click on the add connection and chose mobile broadband from the drop down list.
4. Then chose usb modem configuration option and hit continue
5. select your country and continue
6. select your provider and then on the next page select plan if you have a 3g plan then 7. select web or for 2g select gprs
7. Then apply settings. Okay! you have configured your modem,

now you have to connect to the internet for that click on the networking button again and enable networking if not enabled then you'll see your new connection named with the service provider's name is there . Now just click on that and see if it works. It worked for me. I have a micromax 310g bsnl3g(unlocked)modem using aircel. Hope it'll help.