Comment 0 for bug 1071853

I connect to a mobile broadband network through a Huawei USB 3G modem.
I stay connected all the time.

Every once in a while, with almost systematic periodicity (like every 20-30 minutes), without any apparent reason, whether or not I am using the network or not, the nonnection suddenly goes down, and:
- the indicator shows I'm disconnected, the
- the mobile broadband networks (I have two of them configured, though I only use one now) disappear from the list in nm-applet
- The option "Enable Mobile Broadband" at the bottom of the nm-applet menu DISAPPEARS (not that it gets unchecked, it _disappears_ completely)

In order to reconnect I have to unplug and replug the usb modem, wait a few seconds for it to be initialized or whatever, and then reconnect via the nm-applet (when the nm-applet doesn't become unresponsive because of another old known bug).

All the symptoms are EXACTLY as if someone had suddenly unplogged the modem physically, so this may as well be a usb problem.

I have no idea what logs I should look for and attach.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: network-manager 0.9.4.0-0ubuntu4.2
ProcVersionSignature: Ubuntu 3.2.0-33.52-generic 3.2.31
Uname: Linux 3.2.0-33-generic i686
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu14
Architecture: i386
Date: Fri Oct 26 20:10:24 2012
IfupdownConfig:
 auto lo
 iface lo inet loopback
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
IpRoute:
 default via 10.64.64.64 dev ppp0 proto static
 10.64.64.64 dev ppp0 proto kernel scope link src 77.210.172.228
 169.254.0.0/16 dev ppp0 scope link metric 1000
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
ProcEnviron:
 TERM=xterm
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: network-manager
UpgradeStatus: Upgraded to precise on 2012-05-17 (162 days ago)
mtime.conffile..etc.NetworkManager.NetworkManager.conf: 2012-08-30T13:38:55.126319
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH
 ttyUSB0 gsm connected /org/freedesktop/NetworkManager/Devices/19
 wlan0 802-11-wireless disconnected /org/freedesktop/NetworkManager/Devices/1
 eth0 802-3-ethernet unavailable /org/freedesktop/NetworkManager/Devices/0
nmcli-nm:
 RUNNING VERSION STATE NET-ENABLED WIFI-HARDWARE WIFI WWAN-HARDWARE WWAN
 running 0.9.4.0 connected enabled enabled enabled enabled enabled