2007-05-23 09:55:48

by Joerg

[permalink] [raw]
Subject: RE: [PATCH V6] mac80211: Add support for SIOCGIWRATE ioctl to provide rate information

Hello all,
what does SIOCGIWRATE do for IBSS networks? In this case you might have a different rate for every node in your network. Looking up just "sdata->u.sta.bssid" is insufficient because the BSSID of an IBSS network is not a real MAC address (after all, there is no AP).

I would very much like an official way to enumerate the current rates for all known stations in an IBSS network. This information would be useful for AdHoc routing: Currently most approaches use packet loss to weight different links. In this case a link might look better than it actually is, because rate control already lowered the current rate to a level where no packet loss occured whereas another link with higher data rate looks bad because it drops a packet now and than.

Is there a way to get this information?

--
Regards

Joerg







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2007-05-23 10:16:43

by Johannes Berg

[permalink] [raw]
Subject: RE: [PATCH V6] mac80211: Add support for SIOCGIWRATE ioctl to provide rate information

Joerg,

it is recommended practice to never remove people from CC, that applies
to From: too, so you should have sent a copy of your mail directly to
Larry as well.

> what does SIOCGIWRATE do for IBSS networks? In this case you might
> have a different rate for every node in your network. Looking up just
> "sdata->u.sta.bssid" is insufficient because the BSSID of an IBSS
> network is not a real MAC address (after all, there is no AP).

Nothing. It returns -EOPNOTSUPP, read the code.

> I would very much like an official way to enumerate the current rates
> for all known stations in an IBSS network. This information would be
> useful for AdHoc routing: Currently most approaches use packet loss to
> weight different links. In this case a link might look better than it
> actually is, because rate control already lowered the current rate to
> a level where no packet loss occured whereas another link with higher
> data rate looks bad because it drops a packet now and than.
>
> Is there a way to get this information?

No. Feel free to come up with a spec and implement it for
cfg80211/nl80211

johannes


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