On Fri, 2019-10-25 at 11:17 -0700, Clive McCarthy wrote:
> I've done a quick survey around the building and NM is always
> selecting the highest data rate AP despite stronger signals from
> other APs. This happens even when the data rate difference is
> relatively small.

Again, it's actually the supplicant making the choice. But since NM is
the face of things here, it gets ultimate responsibility for the
behavior I guess.

> As an example:
> > signal 90% data rate 54 Mbps
> > signal 55% data rate 65 Mbps -- active
>  a bad choice. If the signal numbers were in dBm things would be
> clearer. 

Typically you want faster data rates, not stronger signal (to a point).

For example if you were right next to your 802.11g AP with a max of
54Mbps, but had a 50% signal to an 802.11ac AP with a likely rate of
400+Mbps, why would you want to connect to the stronger-but-slower AP?

Dan

> I put my Android phone next to my Linux laptop and got:
> > -48dBm
> > -58dBm
>  respectively for the two channels a ~10dB difference. Way, way more
> that the ratio of 90% to 55%. So forget this % nonsense.
> 
> On 10/23/19 12:41 AM, Thomas Haller wrote:
> > On Tue, 2019-10-22 at 15:02 -0700, Clive McCarthy via
> > networkmanager-
> > list wrote:
> > > You know, I wish that the Network Manager would report the signal
> > > strength in dBm instead of the silly sector icon. But that is for
> > > another day.
> > 
> > nmcli -f SIGNAL,BSSID,SSID device wifi
> > nmcli -f ALL device wifi
> > 
> > 
> > best,
> > Thomas
> > 
> > > On 10/22/19 2:24 PM, Dan Williams wrote:
> > > > On Tue, 2019-10-22 at 13:37 -0700, Clive McCarthy wrote:
> > > > > I rand the commands you suggested but the response doesn't
> > > > > look
> > > > > like
> > > > > a log dump. I guess they just enable logging.
> > > > > 
> > > > > method return time=1571775394.161873 sender=:1.8 ->
> > > > > destination=:1.507 serial=32493 reply_serial=2
> > > > > method return time=1571775429.864202 sender=:1.8 ->
> > > > > destination=:1.508 serial=32496 reply_serial=2
> > > > > method return time=1571775528.578915 sender=:1.8 ->
> > > > > destination=:1.510 serial=32636 reply_serial=2
> > > > > 
> > > > > Can you point me to where the log files might be or at least
> > > > > their
> > > > > names.
> > > > 
> > > > If your distribution uses systemd, they may be available with:
> > > > 
> > > > journalctl -b -u wpa_supplicant
> > > > 
> > > > if your distro does not uses systemd, then it'll be wherever
> > > > syslog
> > > > dumps that kind of output, like:
> > > > 
> > > > /var/log/messages
> > > > /var/log/wpa_supplicant.log
> > > > /var/log/daemon.log
> > > > 
> > > > Dan
> > > > 
> > > > > On 10/22/19 12:16 PM, Dan Williams wrote:
> > > > > > On Tue, 2019-10-22 at 11:17 -0700, Clive McCarthy wrote:
> > > > > > > Thanks for your reply.
> > > > > > > My laptop, when first opened, reports (via the Network
> > > > > > > Manage, I
> > > > > > > suppose) that it is disconnected from the network. After
> > > > > > > a
> > > > > > > second
> > > > > > > or
> > > > > > > two it reports being connected. And it is. However, as I
> > > > > > > noted,
> > > > > > > the
> > > > > > > manager seems to choose the last known connection. This
> > > > > > > is a
> > > > > > > satisfactory algorithm for a fixed computer and for a
> > > > > > > computer
> > > > > > > connecting to a single AP. It isn't good for a movable
> > > > > > > computer
> > > > > > > with
> > > > > > > multiple APs.
> > > > > > > 
> > > > > > > The Intel WiFi adapter is forced to shutdown when the
> > > > > > > computer is
> > > > > > > closed because there is a bug in the Intel-WiFi driver
> > > > > > > that
> > > > > > > doesn't
> > > > > > > handle suspend correctly. That is why there is a
> > > > > > > disconnect-
> > > > > > > connect
> > > > > > > sequence.
> > > > > > 
> > > > > > In this case we'd need the wpa_supplicant logs described
> > > > > > below
> > > > > > to
> > > > > > diagnose why the supplicant is picking that specific AP
> > > > > > rather
> > > > > > than
> > > > > > another.
> > > > > > 
> > > > > > Dan
> > > > > > 
> > > > > > 
> > > > > > > On 10/22/19 10:05 AM, Dan Williams wrote:
> > > > > > > > On Mon, 2019-10-21 at 20:42 -0700, Clive McCarthy via
> > > > > > > > networkmanager-
> > > > > > > > list wrote:
> > > > > > > > > I have a situation where I have multiple APs in a
> > > > > > > > > building
> > > > > > > > > all
> > > > > > > > > with
> > > > > > > > > the same SSID and WPA key but set to non-clashing
> > > > > > > > > frequencies.
> > > > > > > > > When I
> > > > > > > > > close my laptop and WiFi shuts down and I move to a
> > > > > > > > > new
> > > > > > > > > location
> > > > > > > > > the
> > > > > > > > > Network Manager seems to connect to the original AP,
> > > > > > > > > rather
> > > > > > > > > than
> > > > > > > > > one
> > > > > > > > > with a much stronger signal.
> > > > > > > > > 
> > > > > > > > > The algorithm for AP connection is suboptimal (in
> > > > > > > > > other
> > > > > > > > > words
> > > > > > > > > dumb).
> > > > > > > > > The selection process should scan ALL APs, figure out
> > > > > > > > > which
> > > > > > > > > ones
> > > > > > > > > are
> > > > > > > > > known (SSID and WPA); measure their signal strength
> > > > > > > > > and
> > > > > > > > > then
> > > > > > > > > choose
> > > > > > > > > the known AP with the strongest signal.
> > > > > > > > > 
> > > > > > > > > How hard is that?
> > > > > > > > 
> > > > > > > > This is what NetworkManager should already be doing.
> > > > > > > > 
> > > > > > > > Two things to check:
> > > > > > > > 
> > > > > > > > 1) NetworkManager depends on being notified by systemd
> > > > > > > > or
> > > > > > > > upower
> > > > > > > > that
> > > > > > > > the laptop has suspended so that it can reconfigure
> > > > > > > > when it
> > > > > > > > wakes
> > > > > > > > up.
> > > > > > > > It should be pretty clear if that's happening through
> > > > > > > > the
> > > > > > > > NetworkManager logs because it will say that it's going
> > > > > > > > to
> > > > > > > > sleep
> > > > > > > > and
> > > > > > > > waking up. For example:
> > > > > > > > 
> > > > > > > > NetworkManager[1198]: <info>  [1571720491.7590]
> > > > > > > > manager:
> > > > > > > > sleep:
> > > > > > > > sleep requested (sleeping: no  enabled: yes)
> > > > > > > > NetworkManager[1198]: <info>  [1571720491.7599] device
> > > > > > > > (wlp61s0):
> > > > > > > > state change: disconnected -> unmanaged (reason
> > > > > > > > 'sleeping',
> > > > > > > > sys-
> > > > > > > > iface-state: 'managed')
> > > > > > > > NetworkManager[1198]: <info>  [1571720491.7615]
> > > > > > > > manager:
> > > > > > > > NetworkManager state is now ASLEEP
> > > > > > > > NetworkManager[1198]: <warn>  [1571752873.5481] sup-
> > > > > > > > iface[0x55f38553aaa0,wlp61s0]: connection disconnected
> > > > > > > > (reason
> > > > > > > > -3)
> > > > > > > > NetworkManager[1198]: <info>  [1571752873.5504] device
> > > > > > > > (wlp61s0):
> > > > > > > > supplicant interface state: completed -> disconnected
> > > > > > > > NetworkManager[1198]: <info>  [1571752873.5803]
> > > > > > > > manager:
> > > > > > > > sleep:
> > > > > > > > wake requested (sleeping: yes  enabled: yes)
> > > > > > > > NetworkManager[1198]: <info>  [1571752873.6556] device
> > > > > > > > (wlp61s0):
> > > > > > > > state change: activated -> unmanaged (reason
> > > > > > > > 'sleeping',
> > > > > > > > sys-
> > > > > > > > iface-
> > > > > > > > state: 'managed')
> > > > > > > > 
> > > > > > > > 2) enabling debug logging in wpa_supplicant with these
> > > > > > > > two
> > > > > > > > commands
> > > > > > > > will show you exactly what's going on:
> > > > > > > > 
> > > > > > > > sudo dbus-send --system --print-reply --
> > > > > > > > dest=fi.w1.wpa_supplicant1
> > > > > > > > /fi/w1/wpa_supplicant1
> > > > > > > > org.freedesktop.DBus.Properties.Set
> > > > > > > > string:fi.w1.wpa_supplicant1 string:DebugTimestamp
> > > > > > > > variant:boolean:true
> > > > > > > > sudo dbus-send --system --print-reply --
> > > > > > > > dest=fi.w1.wpa_supplicant1
> > > > > > > > /fi/w1/wpa_supplicant1
> > > > > > > > org.freedesktop.DBus.Properties.Set
> > > > > > > > string:fi.w1.wpa_supplicant1 string:DebugLevel
> > > > > > > > variant:string:"msgdump"
> > > > > > > > 
> > > > > > > > this will dump logs to wherever your system typically
> > > > > > > > sends
> > > > > > > > system
> > > > > > > > logs, like the systemd journal or syslog. Once you have
> > > > > > > > these
> > > > > > > > logs,
> > > > > > > > please review them to ensure there is no private
> > > > > > > > information
> > > > > > > > and
> > > > > > > > then
> > > > > > > > attach them to a reply so that we can figure out what's
> > > > > > > > going
> > > > > > > > on.
> > > > > > > > 
> > > > > > > > Thanks!
> > > > > > > > Dan
> > > > > > > > 
> > > > > > > 
> > > > > > >  
> > > > > 
> > > > >  
> > > 
> > >  
> > > _______________________________________________
> > > networkmanager-list mailing list
> > > [email protected]
> > > https://mail.gnome.org/mailman/listinfo/networkmanager-list
>  

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