On Fri, Feb 11, 2011 at 7:06 PM, mike cloaked <[email protected]> wrote: > On Fri, Feb 11, 2011 at 4:30 PM, Sven Nielsen <[email protected]> wrote: >>> > >>> > That is of course fine - but there are use cases where the two APs are >>> > both in one's own home - and both have the same ssid.... and that >>> > presents a problem - at least for me. >>> > >> I cannot see the problem either. I think you are talking about the common >> scenario of having several APs >> physically distributed on a location which are providing the same WLAN (i.e. >> all have identical SSID and >> security settings) to clients. Purpose is to ensure good connectivity around >> the whole facility. >> >> This situation is already handled automatically by Network Manager. Simply >> define a network configuration, >> and do NOT set a bssid. This way, NM can (and will) always and automatically >> connect to the AP with the >> strongest signal. It will also automatically switch to another AP if you >> move out of the range of one AP and >> into the range of another AP. It does this transparently, usually even >> without any noticeable connection >> pause. >> >> DO NOT set the BSSID (MAC) if you want to roam several APs that provide the >> same WLAN. >> >> To optimize WLAN quality, configure APs with distinct channels (e.g. 1 and >> 6) to avoid interferences between >> both signals. > > I don't know if you have actually tried this in a real life situation > or not? However if you do have two access points, and they have the > same ssid, and the same wpa2 encryption with the same password, but > are on different channels (let's say one is upstairs and the other is > downstairs) - then go near access point 1 (let's say it is upstairs) - > and connect - it works really well and indeed you can see which it has > connected to by running "iwconfig" as root. This will show the mac > address of the access point that the wireless is connected to and it > will confirm it has connected to the access point in the same room. > > The signal remains beautifully at about 100% for as long as you like - > and all is sweet. > > Now you turn the laptop off and go to work. > > In the evening you come back home, and being tired you bring the > laptop downstairs and sit on the sofa while you watch the news and > turn on the laptop which is now near the downstairs access point. > You find the signal is really weak and the speed of connection is low > - so you become root and type "iwconfig" - you are amazed that it is > still connecting to the the upstairs access point as you can still see > the same mac address listed. The access point is only 10 feet from > you and if the laptop would only connect to this one you would get a > solid and unwavering 100% signal - but NM refuses to co-operate and > make that connection. > > OK so you are now frustrated - so you go into the NM connections list > and remove the connection that you already have. You do "service > NetworkManager restart" and then when the icon reappears on the gnome > desktop, you click it, and connect to the same ssid name - now it > connects immediately to the near one with 100% signal and you use it > all evening with no problem. > > You shutdown for the night. Next morning you are upstairs and turn on > the laptop - and it now wants to stick with the one downstairs - which > is now very weak because you are upstairs! This is my experience with > more than one laptop - with different wireless cards but all running > Fedora 14. > > So next time I am in the situation where it refuses to connect to the > strong signal I disconnect the wireless and edit the connection in NM > - and add in the MAC address of the near access point into the bssid > field and save the change. Now I can connect to the specific access > point that I want to. > > The point is that I should not need to go through this rigmarole to > connect to a very much stronger access point which is transmitting the > same ssid, password and encryption type as another access point with > the same connection details which is much further away and has a > substantially and consistently weaker signal. >
By the way the whole point of having two access points set up with the same ssid and encryption is that you just connect to a single ssid wherever you are in that location - but NM simply does not seem to behave that way. If you set different ssid on the two access points, then the behaviour I described above still happens if there is any small amount if signal from the access point still seen by the wireless radio - only if there is no signal at all from the previously connected access point will the system then forget the previous connection and try to connect to the near one. I have indeed heard the reasons for why the logic for making the initial connection is the way it is currently but in the scenario I described it would appear to me to be significantly away from the optimum behaviour - If my description is not well phrased I will try to describe it a different way? -- mike c _______________________________________________ networkmanager-list mailing list [email protected] http://mail.gnome.org/mailman/listinfo/networkmanager-list
