Question : Wi-Fi Backhaul

Hello,

We are running into intermittent packet lose and connection drop on a backhaul connection between two buildings connected with wi-fi antennas and APs in bridge mode.  First let me break down the equipment:

Antennas:
Model - CP Technologies Levelone Freecon indoor/outdoor wireless antenna with 8.5 dBi Gain – WAN - 2085

Installation - on the outside of each building with clear line of sight to each other


AP:
Model - Linksys WAP54G v3.0

Installation - Using cable provided with antennas, so no longer the 3 ft. of cable between the antenna and access point.  The AP is mounted inside the buildings.  It is not a cat-5e (wire) issue as we have tested the runs from the APs back to the MDFs thoroughly.


The two building are roughly 100 yards apart.  The antennas do have clear line of sight.  The few points that come to mind are that the buildings are covered on the sides with metal siding that has the perforated edges.  By perforated edges I mean the  sheet metal ridges in and out.  We have even switched the APs to B mode thinking that maybe the metal was causing some odd reflections of signal and that would help.  Though I keep thinking it does have something to do with the metal on the sides, I am at my wits end of how to diagnose further and come to a resolution.  Thanks for any guidance that can be offered.

Answer : Wi-Fi Backhaul

How much packet loss are talking here?  You do 20 pings, how many timeout?

I think you are right about interference, but it could be caused by a lot of things.  Since you are running the connection of the 2.4 ghz range cordless phones and other networks could be causing the issue as well.  

Many cordless phones run on the 2.4 ghz frequency, but there isn't much you can do about this.

One thing you should definitely do is scan the area for other networks.  There is a great utility called network stumbler (www.netstumbler.com).  This will allow you to see what other networks are around and which channel and frequency they are running on.

Depending on what you find in the site survey, you may want to change the channels of your APs.  If you see a lot of other networks using channels 6 and 11, then change the channel to 1.  If other networks are on 1 and 6, then change yours to 11.  And if the other networks are running on channels 1 and 11 then change to channel 6.  The idea is to be on a non-overlapping channel.  Check this site out for more technical info on this: http://www.wi-fiplanet.com/tutorials/article.php/972261  (it talks about Wireless B, but it applies to G as well).

And one last thought...
Many times bridges will be put on the "A" standard because it runs on the 5 ghz frequency which is seldom used (atleast compared to 2.4).  But this would require new hardware...having some new Cisco Aironets wouldn't hurt either.

Hope this helps.

REB