On Sat, 2008-04-19 at 15:51 +0200, Johannes Berg wrote: > > > I'll leave it up to you (collective you, not necessarily a personal > > > you), how to best deal with associating with APs which are not > > > broadcasting their SSIDs. I agree with you (personal you this time) that > > > roaming around the country broadcasting those SSIDs does not seem > > > particularly desirable. So how should the ability to connect to non SSID > > > broadcasting APs be implemented? > > > > I would probably list, in network-manager, "I found (a) hidden > > network(s)" and ask the user for an SSID to scan for actively at that > > particular time, rather than trying to scan for all previously known > > SSIDs even if those networks weren't hidden, as windows laptops (at > > least those with Intel hardware but I haven't seen many others) seem to > > do. > > Or it could remember the BSSID and when it encounters the BSSID again > scan it actively to see if it still has the same (albeit hidden) SSID. That's what NM does; NM will cache the BSSIDs of previously associated APs and use that to determine which APs to connect to automatically. wpa_supplicant, unfortunately, doesn't use this trick when associating (since it doesn't really store state at all), and therefore in the hidden AP case, NM passes "ap_scan=1 + scan_ssid=1" to probe-scan the AP that we want to connect to. But that's still only _one_ AP being probe-scanned, not 4... There's likely some room for improvement in wpa_supplicant here, since there's added latency waiting for the supplicant to do scans when NM already knows exactly which AP/BSSID to connect to already, but we can't push the exact SSID into the supplicant's config, because that would cause the supplicant to only ever assocate with that AP (I _think_ so at least) and therefore not roam correctly. Dan > My N810 behaves that way too, incidentally, it seems to first scan > broadcast but if you then don't select a network quickly it starts > scanning all networks directedly that it has previously saved. > > johannes -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
