It looks like the disconnections are initiated by NetworkManager, which gives the reason 'ip-config-unavailable'. Maybe some kind of dhcp problem, I'm not sure. Right now it isn't looking like a driver problem but something higher in the stack, so I'm updating the bug to affect network manager so that someone more familiar with that level of the network stack can take a look.
** Package changed: linux (Ubuntu) => network-manager (Ubuntu) ** Changed in: network-manager (Ubuntu) Status: Incomplete => Confirmed -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to network-manager in Ubuntu. https://bugs.launchpad.net/bugs/1355441 Title: Wifi dropping Status in “network-manager” package in Ubuntu: Confirmed Bug description: Environment Lenovo T440s Ubuntu 14.04 Kernel: 3.13.0-32-generic #57-Ubuntu SMP x86_64 Firmware version: Aug 11 14:17:58 dave kernel: [ 3.336421] iwlwifi 0000:03:00.0: loaded firmware version 22.1.7.0 op_mode iwlmvm # I have also tried version 22.1.8.0 sudo lshw -C network description: Wireless interface product: Wireless 7260 vendor: Intel Corporation physical id: 0 bus info: pci@0000:03:00.0 logical name: wlan0 version: 83 serial: e8:2a:ea:b3:5a:1f width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=iwlwifi driverversion=3.13.0-32-generic firmware=22.1.7.0 ip=192.168.1.121 latency=0 link=yes multicast=yes wireless=IEEE 802.11abgn resources: irq:61 memory:f0400000-f0401fff sudo iwconfig: wlan0 IEEE 802.11abgn ESSID:"nfu2" Mode:Managed Frequency:2.437 GHz Access Point: 68:7F:74:A2:56:27 Bit Rate=54 Mb/s Tx-Power=16 dBm Retry long limit:7 RTS thr:off Fragment thr:off Encryption key:off Power Management:off Link Quality=70/70 Signal level=-22 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:119 Missed beacon:0 grep wifi /var/log/syslog: Aug 11 14:17:58 dave kernel: [ 3.336421] iwlwifi 0000:03:00.0: loaded firmware version 22.1.7.0 op_mode iwlmvm (30x of these:) Aug 11 16:52:15 dave kernel: [ 9256.926634] iwlwifi 0000:03:00.0 wlan0: disabling VHT as WMM/QoS is not supported by the AP ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-3.13.0-32-generic 3.13.0-32.57 ProcVersionSignature: Ubuntu 3.13.0-32.57-generic 3.13.11.4 Uname: Linux 3.13.0-32-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.3 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC2: dave 1907 F.... pulseaudio /dev/snd/controlC0: dave 1907 F.... pulseaudio CurrentDesktop: Unity Date: Mon Aug 11 16:46:39 2014 HibernationDevice: RESUME=UUID=b447ca85-41cc-44f1-b4b4-8a44bf215053 InstallationDate: Installed on 2014-07-21 (21 days ago) InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417) MachineType: LENOVO 20AQCTO1WW ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-32-generic.efi.signed root=UUID=a5f87e7d-a068-4cf1-94c5-0a4d068328f4 ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.13.0-32-generic N/A linux-backports-modules-3.13.0-32-generic N/A linux-firmware 1.127.5 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 05/20/2014 dmi.bios.vendor: LENOVO dmi.bios.version: GJET77WW (2.27 ) dmi.board.asset.tag: Not Available dmi.board.name: 20AQCTO1WW dmi.board.vendor: LENOVO dmi.board.version: SDK0E50512 STD dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Not Available dmi.modalias: dmi:bvnLENOVO:bvrGJET77WW(2.27):bd05/20/2014:svnLENOVO:pn20AQCTO1WW:pvrThinkPadT440s:rvnLENOVO:rn20AQCTO1WW:rvrSDK0E50512STD:cvnLENOVO:ct10:cvrNotAvailable: dmi.product.name: 20AQCTO1WW dmi.product.version: ThinkPad T440s dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1355441/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp