Wireless for retail store (POS <-> office)

DSLC

Hi, I am considering setting up a wireless LAN for our small retail store. There would be one computer in the office (Level 1), and one at the point of sale (Ground Level). I would quite likely be using a PDA as well for easy stock-taking, and maybe connecting a laptop in the office on occasion. There is actually a lower ground floor as well (with stock in it), so the network would need to cover three floors in total, with each floor about 30-35 metres square (off the top of my head).

I have never set up a wireless LAN before, and was infact just getting used to wired LANs when I realised that, if there is an alternative to getting yards of cables and drilling holes for them, we should consider it. I would just appreciate if someone could point me in the right direction, and alert me of potential problems. Would the area I mentioned above be just outside the bluetooth range? If so, would I just add an access point? Should I use 802.11a or 802.11g cards?

A number of people have advised me against using wireless networks for our purpose (saying that they wouldn't be reliable enough), but I'm hoping you can assure me that their reliability is rock solid - even when installed by a newbie like me.

P.S. The POS and office computers will be running Linux, so everything will have to be Linux compatible. Our distribution comes with drivers for a number of wireless devices installed by default, but I presume there are devices that run on Windows/Mac but not on Linux.

sirlinux

Basically it's very straightforward, you would need at least one access point for each floor, then for your tills, assuming they already run ethernet you can get an ethernet convertor for wireless something like a linksys wet11, at this stage get 802.11g access points, bluetooth is not suitable for this application, what POS hardware/software are you using. From experience with POS stuff it all runs on ethernet so the convertors such as the wet11 will sort you out. Apart from that secure the network, especially if your tills do credit card auths, turn off the ssid broadcast, at the minumum turn on wep.

I would strongly recommend against using a wireless network for your point of sale system. Unless traffic between the POS and the server is secured with VPN or similar you are leaving yourself open to to attack. (I am assuming the POS updates another machine on the network)

WEP security is basicly useless. Given enough time and enough traffic (hours on a relativly busy network) WEP can be sniffed and broken. There are serious flaws with WEP.

The basic answer is yes it can be done easily by yourself but you may want to look into the security side a bit more before making your decision.

Discussion of WEP
http://www.wi-fiplanet.com/tutorials/article.php/1368661

liamo

I fully agree with ronoc.

Reliability and/or Linux compatibility is not the issue here. An unsecured wireless point on an office LAN is an open invitation to all-and-sundry to wander at will around your network.

WEP, as ronoc has already said, is eminently breakable and MAC based filtering is less than useless as MAC-spoofing is a one-liner.

I would only feel comfortable with a wireless node on my network if it was on the other side of a firewall and access to the network resources was via a VPN.

Regards,

Liam

Paddyo

Hi

I think a sense of proportion needs to be applied when talking about the uselessness of WEP.

The only real concern I would have is, as stated by sirlinux, if credit card details are to be passed over the wireless network.

Otherwise, it seems to be a fairly small retail outlet - the infomation being passed is of little consequence to anyone else. Who would be trying to break into the system?

WEP is enough to keep the casual sniffer out.

If they really wanted the info that badly they could simply break and rob the server!

For what its worth ...

Paddyo

liamo

Hi Paddyo. While you make a good point about keeping a sense of proportion, and yes, WEP (and Access Control Lists) will keep the casual sniffer out, it's not just the credit card details, etc that need to be secured, it's access to the entire network.

As to the question of who would be interested in trying to break in? The tech equivalent of anyone who'd put a brick thru your window or "key" your new car. They would do it 'cos they can and/or just felt like it.

If the Access Point was only switched on at intervals (eg for Stock Taking) then I would feel less uncomfortable about using just WEP and ACL. However, if it is to be left on 24/7 then I'd go the VPN route.

Regards,

Liam

DSLC

Hi, thanks for your replies
The POS software we're using (which also happens to be inventory-tracking and accounting software) is SQL-Ledger , which is suitable for use with handhelds, so that's a start.
We have a separate phone line for verifying credit cards, so we won't be transmitting credit card info over the network.
I'll have to think some more about what ye've said though - there's alot of info there for a newb like me. I'd gladly just stick with the wired LAN, which I'm at least partly used to, but ripping up carpets (and maybe even drilling holes) for that cable really would be a pain in the arse.
Cheers

PeteD

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