Subject: Re: ifconfig for wireless LAN
To: None <tech-net@netbsd.org>
From: Jason R Thorpe <thorpej@zembu.com>
List: tech-net
Date: 03/14/2000 08:50:42
On Tue, Mar 07, 2000 at 10:37:27PM +0900, Atsushi Onoe wrote:
> I'd like to propose the changes of ifconfig media/mediaopt for IEEE802.11
> wireless LAN as follows:
> media { infrastructure | adhoc }
> mediaopt [ create-ibss | no-bssid ] [ wep ] [ power-mgmt ]
>
> Comparing with the current usages:
> media { FH1 | FH2 | DS1 | DS2 | DS5 | DS11 }
> mediaopt [ adhoc ]
>
> I think it's not so good at the following points.
> 1. "FH" and "DS" cannot be set at all. It just show the type of
> PHY chip on the card, and printed at attaching the interface
> would be enough.
Hm. That's true. I guess there aren't really any cards that do both :-)
However, it is nice to be able to explicitly set the speed... Although,
I guess this really isn't practically useful, is it...
> 2. Bit rate is not necessarily specified for most cases.
> Both for infrastructure mode and ad-hoc (IBSS) mode,
> spec says that the PHY with multirate support MUST use
> basic rate for multicast/broadcast and control frames,
> and MUST NOT transmit at a higher rate without prior knowledge
> of destination's supported rate, which are shown by beacon
> frames or association requests.
>
> Though only WaveLAN ad-hoc mode may need of fixed rate,
> auto rate select apparently works on WaveLAN ad-hoc mode.
>
> 3. The infrastructure mode and the ad-hoc mode are clearly different
> and cannot interoperable each other. So they cannot be "media
> options" but mutually exclusive "media types".
Hm, that's true.
> And there are some more options to be defined for wireless LAN.
> create-ibss Create its own IBSS and announce it when it fails
> to find or join existing IBSS.
> Only valid for the adhoc media type.
> Note that isolated two node with this option
> cannot talk to eath other even if they come closer
> again.
> no-bssid Do not use bssid nor beacons at all. It is just
> same as adhoc mode of WaveLAN (wi(4)).
> Only valid for the adhoc media type.
I assume that no-bssid would be the default for adhoc always? How is this
different from any other adhoc mode, or is adhoc on the `wi' not interoperable
with the adhoc mode on e.g. `ray'? (ignoring the FH/DS issue...)
> wep Enables WEP (Wired Equivalent Privacy). It requires
> WEP encryption to communicate others.
> power-mgmt Enables power management capability. Only available
> for infrastructure media type and it requires
> additional support by access points.
>
> Possibly more to be defined somewhere:
> desired ESSID currently can be specified by the "nwid" parameter of
> ifconfig(8). Empty string ('') means wildcard
> ESSID which allow to connect any access points.
> created ESSID used for "create-ibss". It may be the same string
> with desired ESSID but it should not be empty.
> WEP key used for "wep" encryption/decryption.
> channel/pattern used for "create-ibss" to determine the radio
> frequency (DS) or hopping pattern (FH) to be used
> to create IBSS. Also used for "no-bssid".
All of these could be handled with ifconfig, I think. "created ESSID"
could be "cessid".
> Though I'm not quite sure whether these parameters should be specified
> by ifconfig, I don't hope there are so many XXXconfig commands...
I think they should be. Seems silly to have a separate program to do
all this stuff when it can be reasonably handled by ifconfig(8).
Ignore the fact that ifconfig(8) is a pile of junk inside :-)
> Any comments?
Only the ones above :-) I'd like to hear comments from Chris Hopps
and Bill Sommerfeld on this issue, tho.
--
-- Jason R. Thorpe <thorpej@zembu.com>