On Sun, 7 Aug 2005 00:16:44 +0000 (UTC), rel <relic@home.nl> wrote:

>The distance between objects is 1.5km, there is one building between the two buidlings that is 5 meters higher:

Higher than what? Do you have an obstructed line of sight? Do you
have Fresnel zone clearance? If not, you're about to have a
reliability problem.
http://gbppr.dyndns.org:8080/fresnel.main.cgi
You need a radius of about 7 meters clearance at midpoint. Do you
have clearance?

Yeah, I know RedLine claims that the AN-50 is NLOS because it does
OFDM. I think NLOS is science fiction and marketing hype.

You topology description is vague, ambiguous, and lacking in important
detail.
How far apart are A -> B1? (Redline)
How far apart are B2 -> C? (Cisco)
Which path has the building obstruction? Any other obstructions?

>Object "A" a "Redline AN-50", whitch operates on 5.4Ghz, 36Mb/s and setup as accesspoint.

http://www.redlinecommunications.com..._overview.html
>Object "B1" a Redline (same device) but setup as a repeater.

Huh? Why a repeater? To what wireless device are they repeating to?
Methinks this is misconfigured or you're using the wrong buzzword.
Methinks both Redline boxes should be setup as a transparent bridge.

I'll make a guess(tm) and assume that B1 and B2 are located near each
other and connected with an ethernet cable. Is this correct?

>Object "B2" a Cisco Aironet 350, 2.4Ghz. 11Mb/s setup as repeater.
>Object "C" the same Aironet setup as AP.

The Cisco 350 doesn't act as a repeater so methinks you're using the
wrong term here. There are also multiple models of the Cisco 350. My
guess(tm) is that both Cisco 350's should be setup as wireless
transparent bridges.

>The ping results are good, 9ms peeks to 32ms. But when testing the speed by copying a large file from a fileserver, the download started at 30KB/s and then dropped to 8KB/s.
>Avarages at 12KB/s

9msec for such a system sucks. Something is wrong. Even the most
disgusting point to point wireless 802.11b link will do <3msec pings.
The Redline should do even less.

Also, you should do pings with large packets and only one link at a
time. I assume that *ALL* the wireless drives have IP addresses and
can be pinged. Try pinging all of them in sequence and record the
numbers. Methinks you'll find an excessive delay or packet loss in
one of the links.

As for the 12KBytes/sec (or 96kbits/sec), this is incredibly slow.
You have something eating packets along the way. There's not enough
info here to determine the cause, but look for packet loss somewhere.
The management interfaces for the RedLine and Cisco boxes all have
signal strength, signal quality, and error count status pages. Use
these to determine if you have an RF problem.

One common problem I've seen is NWAY negotiation failure. Both Cisco
and Redline have NWAY negotiation at the ethernet interfaces.
However, there's no guarantee that they actually setting on the
correct protocol. I've seen pairs of devices which settle on
100baseTX, but with FDX on one end, and HDX on the other. It works,
but the error rate is horrible. If you suspect this problem, make
sure the ethernet interfaces are set to fixed and identical speeds.
To get 48Mbits/sec thruput, you'll need either 100baseTX-HDX or
preferably 100baseTX-FDX (full duplex).

>Could there be a misconfiguration of the hardware, or what can
>be the problem here. If someone can hint me, please.

This is a rather poor design. You have a top of the line, premo
5.6Ghz wireless bridge running in an obstructed path. It's capeable
of doing 48Mbits/sec thruput, but you have it throttled with a pair of
comparatively slow 802.11b bridges which are limited to perhaps
5Mbits/sec on a good day, and probably 3Mbits/sec typically. Even if
it had worked as intended, it still would be running well under
expectations. Methinks you need to yell at whomever sold you this
mess.

Divide the puzzle in half. Plant yourself with a laptop at B1-B2 and
unplug each end. Ping away in both directions and see which part of
the link is having a problem. It could easily be both. Then, ask the
experts that sold you this abomination why they left without any real
thruput testing.

What does this thing do? What level of sustained thruput are you
expecting?


--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
AE6KS 831-336-2558