Re: Network Manager, misbehaves

[Dan Williams <dcbw redhat com>]

On Mon, 2007-02-12 at 18:42 -0800, Patton Echols wrote:
> I have two issues with Network Manager that I think are related, but 
> perhaps not. 
> 
> Note: Using Ubuntu Edgy
> 
> First, I have the Network Monitor applet showing that I have a 
> connection, as of now, connection strength is at 86%. At the same time 
> Network Manager (0.6.3) shows connection strength at 52%. (25' 
> unobstructed line of sight)  I understand this is a known issue with 
> Atheros chipset cards.  And I saw at one point a fix.  The problem is 
> that the fix required hacking some element of the NM source and 
> recompiling.  While I'd be willing to give such a fix a try, the entire 
> discussion assumed at least some modicum of programing ability.  I'm 
> willing to learn, but that's not me.  The other issue is that I 
> understand the fix would then "break" the ability to have Ubuntu 
> auto-majically update when necessary.  I'm not sure that's a good idea.
> 
> Second problem: My wifi connection will periodically drop connection. 
> This will happen both on my office WIFI or at Home, Both APs are 
> configured for WPA personal. The router / DHCP server at work is 
> configured for 1 day lease times, so I doubt that is the issue.  It will 
> also happen more often when I move to a location, office or home, that 
> has a lower signal strength. 
> 
> It has also happened on Open WIFI.  For example (and this was really 
> frustrating) I was at a hotel at a business conference. There was paid 
> wifi in the rooms and free in the lobby.  So naturally, I went to the 
> lobby, where NM could "see" both the "GuestRm" ESSID and the "Lobby" 
> ESSID.  NM showed about 35% signal strength for the former and <20% for 
> the latter. (Even though I was sitting in the lobby.)  I could force a 
> connection to "Lobby", but would promptly (2-3 minutes) be dropped, and 
> NM would try to access the pay service.  One more data point:  Since I 
> had work that had to be done, I rebooted into XP, forced the "Lobby" 
> connection, and windows was able to stay connected.
> 
> So, if this signal strength discrepancy issue is the culprit, then I'd 
> like to fix it.  But, If the signal strength that NM reports has no 
> effect on NM's functioning, then I suppose I don't care.  Does anyone know?

Signal strength has no effect on NM's function precisely because every
driver used to report it differently.  We harmonized most of the other
drivers, but madwifi still reports oddly.  I don't know if that's
because their not following my interpretation of the WEXT spec or what,
since the WEXT spec is so muddled there.

> Also, anyone have any ideas about why NM drops the connection 
> periodically?  Especially if it is  not about signal strength?

Run 'iwevent' and see if the driver is sending IWAP events with a BSSID
of 00:00:00:00:00:00 when you get disconnected.  If so, that's a driver
problem.  Logs would also help here, they are dumped to the normal
syslog location, usually /var/log/messages.

Dan