Re: Reconciling autoscan/bgscan intervals and default bss expiration age
On 5/19/15, 2:19 PM, "Tomasz Bursztyka" wrote: >Hi Adam, > >> I¹m trying to understand the the bgscan and autoscan parameters in >>plugins/wifi.c - specifically the maximum/long intervals of 300 seconds. >> With the supplicant¹s default BSS Expiration Age of 180 seconds, this >>results in premature aging of the BSSs, resulting in an empty services >>list or perhaps worse, an inability to roam or recover from a lost >>association. I could always tweak these settings or increase the age in >>the supplicant - but I¹m curious why I would need to change something >>like this out of the box - perhaps I¹m missing something. > >The point of autoscan is not to keep alive the list of BSS. It is to be >able to find a service at some point, if you were moving around, while >being disconnected. >Scanning is expensive from power consumption point of view, thus an >exponential delay with a limit of 300 seconds of automatic scanning. >If you reach this limit of 300 seconds without being connected this >means there is no know service around, so no need to pursue expensive >scanning. > >That said, this is relevant as long as you - as the user - do not >request a scan by yourself. If you do so, this will reset the autoscan >counter back. Thanks very much for the explanation, Tomasz! I'll use my own aggressive periodic scan when I want to build a user facing list, and rely on autoscan only for seeking out pre-existing connections. > >About bgscan: this one is in use when you are connected, to roam if the >AP setup supports it. > >> I may also ask the supplicant mailing list why they use these >>configurations in their examples as well, but I thought I¹d start here. > >autoscan is now connman-based only. As the wpa_supplicant's module does >not handle hidden services. >bgscan is ran in wpa_supplicant, the parameters we give are the default >one which are usually ok. >But it might depend on the wifi card and its driver (sometime the signal >threshold is wrongly calculated there, so it only triggers when you are >out of reach already) > >Tomasz >___ >connman mailing list >connman@connman.net >https://lists.connman.net/mailman/listinfo/connman Statement of Confidentiality The contents of this e-mail message and any attachments are confidential and are intended solely for the addressee. The information may also be legally privileged. This transmission is sent in trust, and the sole purpose of delivery to the intended recipient. If you have received this transmission in error, any use, reproduction or dissemination of this transmission is strictly prohibited. If you are not the intended recipient, please immediately notify the sender by reply e-mail or at 508.683.2500 and delete this message and its attachments, if any. ___ connman mailing list connman@connman.net https://lists.connman.net/mailman/listinfo/connman
Re: Reconciling autoscan/bgscan intervals and default bss expiration age
Hi Adam, I’m trying to understand the the bgscan and autoscan parameters in plugins/wifi.c - specifically the maximum/long intervals of 300 seconds. With the supplicant’s default BSS Expiration Age of 180 seconds, this results in premature aging of the BSSs, resulting in an empty services list or perhaps worse, an inability to roam or recover from a lost association. I could always tweak these settings or increase the age in the supplicant - but I’m curious why I would need to change something like this out of the box - perhaps I’m missing something. The point of autoscan is not to keep alive the list of BSS. It is to be able to find a service at some point, if you were moving around, while being disconnected. Scanning is expensive from power consumption point of view, thus an exponential delay with a limit of 300 seconds of automatic scanning. If you reach this limit of 300 seconds without being connected this means there is no know service around, so no need to pursue expensive scanning. That said, this is relevant as long as you - as the user - do not request a scan by yourself. If you do so, this will reset the autoscan counter back. About bgscan: this one is in use when you are connected, to roam if the AP setup supports it. I may also ask the supplicant mailing list why they use these configurations in their examples as well, but I thought I’d start here. autoscan is now connman-based only. As the wpa_supplicant's module does not handle hidden services. bgscan is ran in wpa_supplicant, the parameters we give are the default one which are usually ok. But it might depend on the wifi card and its driver (sometime the signal threshold is wrongly calculated there, so it only triggers when you are out of reach already) Tomasz ___ connman mailing list connman@connman.net https://lists.connman.net/mailman/listinfo/connman
Reconciling autoscan/bgscan intervals and default bss expiration age
Hi all, I’m trying to understand the the bgscan and autoscan parameters in plugins/wifi.c - specifically the maximum/long intervals of 300 seconds. With the supplicant’s default BSS Expiration Age of 180 seconds, this results in premature aging of the BSSs, resulting in an empty services list or perhaps worse, an inability to roam or recover from a lost association. I could always tweak these settings or increase the age in the supplicant - but I’m curious why I would need to change something like this out of the box - perhaps I’m missing something. I may also ask the supplicant mailing list why they use these configurations in their examples as well, but I thought I’d start here. Thanks! Adam Statement of Confidentiality The contents of this e-mail message and any attachments are confidential and are intended solely for the addressee. The information may also be legally privileged. This transmission is sent in trust, and the sole purpose of delivery to the intended recipient. If you have received this transmission in error, any use, reproduction or dissemination of this transmission is strictly prohibited. If you are not the intended recipient, please immediately notify the sender by reply e-mail or at 508.683.2500 and delete this message and its attachments, if any. ___ connman mailing list connman@connman.net https://lists.connman.net/mailman/listinfo/connman
