further information on previous 802.11 thread?

[Mark Purcell]

On Thu, Apr 25, 2002 at 03:42:27AM +1000, clug at repose.cx wrote:
> I'm starting to think about playing with wireless. It's still a bit more
> expensive than I'd like, but I don't think the other members of the household
> appreciate the Cat-5 which is currently running into our living room. :-)

I took the plunge about a month ago and haven't looked back.  It's great.
I picked up a pair of PCMCIA Cabletron Roam Abouts (802.11b) for $130 ea on
sold.com.au.  The guy was selling around a 130 so he may still have some
left. I have an old PCI/PCMCIA adaptor in my gateway box which works fine.

> I was just wondering if anyone was willing to field some 802.11 / linux
> questions.

Fire away, but the best source I found was the Linux Wireless Howto which
gave great details on card compatibility and which drivers work with which
cards. http://www.hpl.hp.com/personal/Jean_Tourrilhes/Linux/
  
> 1. I'd like to use two cards, and avoid the base station, as I really don't
>    want to incure the extra expense. I seem to recall that doing this is when
>    the cards are placed in "ad-hoc" mode, but there's this small piece of
>    information floating around in my head that says that you require
>    new/particular cards to do this nicely without a base station. Am I
>    imagining things? Can base-station-less operation be done fine with no
>    consideration as to the type of card? I just remember reading somewhere
>    about a "better" way to do it, or something. Maybe it was making one of the
>    cards act like an access point?

I have my cards both running in adhoc mode without problem.  But then again
your mileage can vary depending on the cards.  But generally if a card
supports the Linux wireless extenions you should be able to run ad-hoc
mode. Aparently some guy has got developed some software to allow you
to run a Prism2 based card as a base station!  I don't have Prism2 cards so
didn't get any further...

It's called hostap http://people.ssh.com/jkm/Prism2/
 
> 2. I'm wondering what justifies the disparity in pricing between, say, the
>    d-link/netgear cards, and that of orinco, IBM, etc. Is it just the level of
>    WEP encryption (which i'm not interested in, as I'll be using ipsec), or is
>    there more to it than that? Are the "silver" and "gold" cards just different
>    WEP encryption levels?

WEP is a big part of it, not that it is actually worth it. The other factor
is the quality etc...  Standard routine, you can get some really cheep
and nasty cards which don't do Linux only provide prioprity interfaces or
you can go the other end with the fully optioned.  Again look at the HOWTO
above for details.
  
> 3. The gateway I've got set up for our house is in our storeroom. This would be
>    the computer I'd be most interested in connecting one of the access cards to
>    (by way of a pci<->pcmcia convertor), as it's the only computer that never
>    gets turned off for any reason. Our storeroom is made of concrete and brick,
>    however. Would this likely impact on the performance of the wireless link?
>    I'm only interested in setting up a wireless network through the house, so
>    it's likely the other card will be close by - at most 2-3 rooms away. 

I'm afraid to tell you but electrons don't like flying through very solid 
things like concrete and brick! I would imagine you would get sevre degradation
for your network, especially if your storeroom is sealed like a box..  Some
of the more expensive cards do allow external antennas to be connected, so
that maybe of some use, but as you say cumbersom. Another alternative is
to pay $25 for an old 486/ pentium and host your access point outside the store
room. The machine doesn't need a lot of grunt.
  
> I guess what I'm interested in is if the wireless market is a bit like the
> ethernet market, where a standard 8139 card will do the job fairly well, but
> spending more money on a better card will see you hit closer to the 100Mbit
> maximum.

Pretty much, but the extra cost for an external aeriel maybe a requirement for
you.

Mark