State of roaming support in wpa_supplicant 0.5.7

LTI. - Ticmanis, Linards LTI
Wed Feb 14 04:08:55 PST 2007

Hello all,

I would like to know, what is the state of seamless roaming support in wpa_supplicant 0.5.7 if the driver does not do its own roaming.

Specifically, I would like the following to happen in WPA-PSK mode:

1.) Scan regularly even while associated.
2.) If another AP has decidedly better signal level than the one we're on, reassociate with that other AP. Don't wait until the first AP is totally out of range.
3.) Do a decent handoff that minimizes the amount of lost pings (or other lost data).

I'm using the following configuration:


With this configuration, the supplicant issues scans regularly, but doesn't switch APs until the connection has been lost, which means a good number of lost pings, about 5-10 seconds without any connectivity, and of course frequent retransmits in the case where the first AP never goes out of range completely but the signal gets pretty bad.

Is it possible to do what I want to do with wpa_supplicant? Or do I need to implement roaming in the driver in this case?

On first glance, the function wpa_supplicant_select_bss() in events.c doesn't seem to contain any prioritizing by signal quality. Am I correct that no such prioritizing takes place in the supplicant at this time?

I'd be glad for any help.

Best wishes,
Linards Ticmanis
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