What kit do I need? Joining 2 networks

13 Feb 2005 12:53 PM

brodders

Hi,

Helping a friend out here - but wireless kit is not my forte...

He runs a small business with two long (400 ft) buildings some 500 feet
apart - with a road running between them.

Essentially, the buildings are end-to-end with the road seperating
them. So the far ends are way apart - but there is a nice line of sight
between the ends next the road.

Both buildings have Ethernet LAN - and he'd like to join them together.

Also, broadband is due to arrive this year (at last!) so one side needs
a ADSL modem + firewall as well as a 802.11g -ish link.

He wants to keep the existing LAN's, NICs etc. Just bridge the road and
join the LAN's. (BTW this is in UK and throwing a wire across the road
is illegal)

So, I'm thinking that two boxes are needed with LAN I/O - one with a
modem / firewall. It'd be nice to have a mini-hub in that box too.

The modem/firewall/hub/wireless box sounds pretty much standard but I'm
not sure about the kit needed at the other end.

Also, will standard antenna be OK with a 500ft line of sight?? Will I
need some sort of hi-gain antenna at each end?

Your advices please! What do we need buy??

Thanks,

brodders

13 Feb 2005 3:40 PM

Eras

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"brodders" <brodd***@gmail.com> wrote in message
> Hi,
>
> Helping a friend out here - but wireless kit is not my forte...
>
>
> He runs a small business with two long (400 ft) buildings some 500 feet
> apart - with a road running between them.
>
> Essentially, the buildings are end-to-end with the road seperating
> them. So the far ends are way apart - but there is a nice line of sight
> between the ends next the road.
>
> Both buildings have Ethernet LAN - and he'd like to join them together.
>
> Also, broadband is due to arrive this year (at last!) so one side needs
> a ADSL modem + firewall as well as a 802.11g -ish link.
>
> He wants to keep the existing LAN's, NICs etc. Just bridge the road and
> join the LAN's. (BTW this is in UK and throwing a wire across the road
> is illegal)
>
>
> So, I'm thinking that two boxes are needed with LAN I/O - one with a
> modem / firewall. It'd be nice to have a mini-hub in that box too.
>
> The modem/firewall/hub/wireless box sounds pretty much standard but I'm
> not sure about the kit needed at the other end.
>
> Also, will standard antenna be OK with a 500ft line of sight?? Will I
> need some sort of hi-gain antenna at each end?
>
> Your advices please! What do we need buy??
>
> Thanks,
>
> brodders

Sounds like you are looking to do a wireless bridge. Two consumer AP's
capable of "Bridge Mode" should do just this, but the distance (500 feet)
may be outside their range with standard omni-directional antennas. May
have to look at directionals, parabolics, or if you want to go cheap do a
google for "cantennas" -- which are antennas contructed out of all things,
tin soup cans and/or Pringles potato chip cans. One of these days, I've
been planning to make one myself "just for fun".

http://www.turnpoint.net/wireless/cantennahowto.html
(Has a script on that web site that'll do some of the calculations for you.
Don't know how accurate the formulas are though.)

Will your LOS shot be able to go across traffic traveling down the street?
I.e., set your shots from a roof so it'll go over traffic? (When I was in
the Air Force, I had a shot (about a mile long running in 4 to 4.5 Ghz
range) that would intermittingly break during the course of a day. Turned
out aircraft passing over a particular piece of the tarmac were breaking the
shot up. After masting the antenna's at 100 feet, the shot became rock
solid.) :^)

802.11a (5 Ghz) may be more reliable than 802.11g (2.4 Ghz) for such a shot
as well, but it would definetly add a lot more expense. Here, in the US,
consumer wifi manufacturers are finally being able to release 802.11a
consumer hardware with removeable antennas. (Not that fixed antennas has
stopped anyone from doing homebrew 802.11a antennas in the past, but..)

Cheers!

13 Feb 2005 7:50 PM

merv.hrabi

check out external directional antennas

for example Cantenna - www.cantenna.com/

of course the AP's that are used will need to have external antenna
connectors