[Pkg-utopia-maintainers] Bug#742180: network-manager: Wireless connection frequently stalls (on background network scan?)

Thu Mar 20 11:04:45 UTC 2014

Package: network-manager
Version: 0.9.8.0-5
Severity: normal

Dear Maintainer,

my wireless connections frequently stall for around a second (i.e., no packages go through).
This can be reproduced with the following two test cases:

* Download a large file via wget. Observe that pretty precisely every 2 minutes, the
  download bandwith drops to 0 for around a second, then it goes back up again.

* Run "ping ct.de" (or any other host, of course).
  Observe that pretty precisely every 2 minutes, the ping time goes up significantly:

  64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=510 ttl=247 time=22.2 ms
  64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=511 ttl=247 time=62.2 ms
  64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=512 ttl=247 time=254 ms
  64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=513 ttl=247 time=175 ms
  64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=514 ttl=247 time=101 ms
  64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=515 ttl=247 time=22.0 ms
  64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=516 ttl=247 time=21.8 ms
  [ 120 ICMP packages later ]
  64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=629 ttl=247 time=22.5 ms
  64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=630 ttl=247 time=22.5 ms
  64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=631 ttl=247 time=261 ms
  64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=632 ttl=247 time=187 ms
  64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=633 ttl=247 time=108 ms
  64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=634 ttl=247 time=29.5 ms
  64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=636 ttl=247 time=23.4 ms

This is particularily annoying when using VoIP applications like Mumble or TeamSpeak:
These connection stalls are audible as artifacts of the other speakers, and
similarily, the others only get artifacts from me at that time.

I suspect that the cause for these stalls are background network scans:
If I run something like
  watch -n 20 "sudo /sbin/iw dev wlan0 scan"
I can see these stalls every 20 seconds.

I suspect it's NetworkManager doing the 2-minute background scan as this is mentioned
in <https://bugzilla.gnome.org/show_bug.cgi?id=513820>. That thread (and some others)
also mention that fixes for this would be underway in the kernel, but that was three
years ago, so I suspect these fixes never came or did not work? I am not sure
whether this bug ought to be assigned to NetworkManager or to the kernel, so
I'd appreciate help in tracking down the cause of the issue, and the right place
to fix it.

Kind regards
Ralf

-- System Information:
Debian Release: jessie/sid
  APT prefers testing
  APT policy: (990, 'testing'), (100, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.13-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages network-manager depends on:
ii  adduser                3.113+nmu3
ii  dbus                   1.8.0-2
ii  isc-dhcp-client        4.2.4-7
ii  libc6                  2.18-4
ii  libdbus-1-3            1.8.0-2
ii  libdbus-glib-1-2       0.102-1
ii  libgcrypt11            1.5.3-3
ii  libglib2.0-0           2.38.2-5
ii  libgnutls26            2.12.23-13
ii  libgudev-1.0-0         204-7
ii  libnl-3-200            3.2.21-1
ii  libnl-genl-3-200       3.2.21-1
ii  libnl-route-3-200      3.2.21-1
ii  libnm-glib4            0.9.8.0-5
ii  libnm-util2            0.9.8.0-5
ii  libpolkit-gobject-1-0  0.105-4
ii  libuuid1               2.20.1-5.6
ii  lsb-base               4.1+Debian12
ii  udev                   204-7
ii  wpasupplicant          1.1-1

Versions of packages network-manager recommends:
ii  crda          1.1.2-1
ii  dnsmasq-base  2.68-1
ii  iptables      1.4.21-1
ii  modemmanager  0.5.2.0-2.1
ii  policykit-1   0.105-4
ii  ppp           2.4.5+git20130610-4

Versions of packages network-manager suggests:
ii  avahi-autoipd  0.6.31-4

-- Configuration Files:
/etc/NetworkManager/NetworkManager.conf changed:
[main]
plugins=ifupdown,keyfile
no-auto-default=10:BF:48:05:C7:F7,
[ifupdown]
managed=false

/etc/polkit-1/localauthority/10-vendor.d/org.freedesktop.NetworkManager.pkla [Errno 13] Permission denied: u'/etc/polkit-1/localauthority/10-vendor.d/org.freedesktop.NetworkManager.pkla'

-- no debconf information