Slow wifi connection with Cisco EPC3928 modem

[Tomas Mrozek]

I experience very slow download speed when connecting to a Cicso EPC3928 cable modem. The speedtest.net reports about 0.2Mbps download speed and 1.1Mbps upload speed (obvious discrepancy). If I connect to the modem via network cable, the speed gets to 30Mbps/1.1Mbps (that's the expected speed for my line). If I connect a different device over wifi I get 5Mbps/1.1Mbsp (acceptable for a wifi connection). My conclusion therefore is that the problem lies in the wifi connection between my computer and the cable modem and is not due to any other devices in the network.

The wifi connection was working well in the past with other routers. As there were no problems I never measured the speed. Currently I don't have access to any other wifi router/modem that I could connect to and measure the speed.

After extensive Googling, the only widely mentioned possible cause that I found was 802.11n protocol so I tried to disable it with "options iwlwifi 11n_disable=1". However, this had no effect whatsoever.

The cable modem has been provided by the ISP and I currently cannot access its config to gather more info or test different settings in order to pinpoint possible causes for this problem.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: linux-image-3.11.0-18-generic 3.11.0-18.32
ProcVersionSignature: Ubuntu 3.11.0-18.32-generic 3.11.10.4
Uname: Linux 3.11.0-18-generic x86_64
ApportVersion: 2.12.5-0ubuntu2.2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: tom 2398 F.... pulseaudio
 /dev/snd/pcmC0D0c: tom 2398 F...m pulseaudio
Date: Sat Mar 8 15:36:21 2014
HibernationDevice: RESUME=UUID=701b120a-4cbb-47df-b530-32c017d392ee
InstallationDate: Installed on 2014-01-03 (64 days ago)
InstallationMedia: It
MachineType: LENOVO 10115
MarkForUpload: True
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.11.0-18-generic root=UUID=38a215c9-0e4f-4726-9b3b-3f749f762783 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.11.0-18-generic N/A
 linux-backports-modules-3.11.0-18-generic N/A
 linux-firmware 1.116.2
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 01/18/2013
dmi.bios.vendor: LENOVO
dmi.bios.version: EZKT16AUS
dmi.board.name: INVALID
dmi.board.vendor: LENOVO
dmi.board.version: No DPK
dmi.chassis.type: 3
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnLENOVO:bvrEZKT16AUS:bd01/18/2013:svnLENOVO:pn10115:pvrIdeaCenterQ190:rvnLENOVO:rnINVALID:rvrNoDPK:cvnLENOVO:ct3:cvrChassisVersion:
dmi.product.name: 10115
dmi.product.version: IdeaCenter Q190
dmi.sys.vendor: LENOVO

[Brad Figg (brad-figg)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.14 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.14-rc6-trusty/

[Tomas Mrozek (u-mail-j)]

Tested a couple of times with both "3.14.0-031400rc6-generic" and "3.14.0-031400rc6-lowlatency". Nothing improved. The download speed stays at 0.05 Mbps - 0.36 Mbps range while the upload speed remains consistently at 1.58 Mbps.