[plug] Wireless LAN

[Leon Brooks]

Subba Rao wrote:
> I am looking to setup a wireless LAN. The LAN will have
> Linux, NT and Win95 boxes. There are several questions
> that are new to me.

> 1. [a] Will the current ethernet interfaces be sufficient or do I
>    need to replace them? [b] What type of HW is required?

(a) maybe, because (b) that varies between setups. Some wireless LAN
systems are designed to be a card that conceptually replaces your LAN,
others are designed to plug into a LAN. The advantages in the former are
simplicity and lower cost per unit; in the latter the units can be
shared between physically proximate nodes and the transmitter can be
sited to take better advantage of local topography (e.g. to "see over"
metal partitioning or be bolted onto a building outside a window to
"see" other buildings or between floors of the same building.

> 2. What type of hubs are required?

See 1(b).

> 3. How is the security of the hosts on a wireless LAN guaranteed?

Usually not, except in that the transmission range is limited. The
paranoid among us may wish to turn their offices into a Faraday cage by
adding grounded conductive film to all windows and doors and termi-mesh
to all ducting outlets. Some systems to DES-II encryption on the fly.
Linux systems can use a variety of transmission encryption schemes such
as IPSec.

> 4. Last but the least, how expensive is it?

Yes. Varies from about $250 a node to about $20,000 a node, depending on
needs such as range, bandwidth, encryption etc. Single-office systems
rarely exceed $1000 a node; 50km microwave links rarely come cheaper
than $20k per end.

If range is important but you couldn't give two hoots about bandwidth
(e.g. remote level-sensor monitoring), consider AX25 packet radio. TNCs
are cheap, and you can even use a sound card at a pinch.

> I would appreciate your experiences with Linux wireless LANs.

I would appreciate the opportunity to broaden my experience with Linux
wireless LANs. (-:

-- 
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