Customer kills AP

Hello all,

We have a customer who is roughly 5km away from our PoP in the area.
The PoP has three 802.11b AP's, each with a 120 degree sector attached
to it. When we connected this customer with a 24dBi antenna, he had a
strength of over 90% and it killed all the other customers on the AP.
In doing flood pings, some people were dropping over 20% of packets, and
when we turn him off, they go back down to under 5%.

So, we figured he was too powerful and put him down to a 19dBi antenna,
but still, he is killing everyone. Even if we transfer him to a sector
that is facing another direction, he kills everyone -- on all three
sectors. With a 19dBi, his signal strength is still over 80%.

I am wondering if there is anyone here who can help me find out what
else could be causing this problem, or any suggestions to fix it.

BTW - the AP's are Tranzeo TR-4500's (17dBi), and the CPE is a Senao CB3.

Thanks in advance,
Kevin Brown.

Take his amp off him or threaten to cut him off.


"Kevin Brown" <-NOSPAM-itismekevinb-NOSPAM-@hotmail.com> wrote in message
news:m8cGe.1534$6C.512@read2.cgocable.net...
> Hello all,
>
> We have a customer who is roughly 5km away from our PoP in the area. The
> PoP has three 802.11b AP's, each with a 120 degree sector attached to it.
> When we connected this customer with a 24dBi antenna, he had a strength of
> over 90% and it killed all the other customers on the AP. In doing flood
> pings, some people were dropping over 20% of packets, and when we turn him
> off, they go back down to under 5%.
>
> So, we figured he was too powerful and put him down to a 19dBi antenna,
> but still, he is killing everyone. Even if we transfer him to a sector
> that is facing another direction, he kills everyone -- on all three
> sectors. With a 19dBi, his signal strength is still over 80%.
>
> I am wondering if there is anyone here who can help me find out what else
> could be causing this problem, or any suggestions to fix it.
>
> BTW - the AP's are Tranzeo TR-4500's (17dBi), and the CPE is a Senao CB3.
>
> Thanks in advance,
> Kevin Brown.

On Thu, 28 Jul 2005 17:20:51 -0500, Kevin Brown
<-NOSPAM-itismekevinb-NOSPAM-@hotmail.com> wrote:

>We have a customer who is roughly 5km away from our PoP in the area.
>The PoP has three 802.11b AP's, each with a 120 degree sector attached
>to it. When we connected this customer with a 24dBi antenna, he had a
>strength of over 90% and it killed all the other customers on the AP.
>In doing flood pings, some people were dropping over 20% of packets, and
>when we turn him off, they go back down to under 5%.
>
>So, we figured he was too powerful and put him down to a 19dBi antenna,
>but still, he is killing everyone. Even if we transfer him to a sector
>that is facing another direction, he kills everyone -- on all three
>sectors. With a 19dBi, his signal strength is still over 80%.
>
>I am wondering if there is anyone here who can help me find out what
>else could be causing this problem, or any suggestions to fix it.
>
>BTW - the AP's are Tranzeo TR-4500's (17dBi), and the CPE is a Senao CB3.

I guess you're a WISP. You might try asking the same question in the
mailing lists at:
http://www.wispa.org
http://isp-wireless.com

My guess(tm) is that you have a classic hidden transmitter problem.
With highly directional antennas at the client end, none of the
clients are going to hear each other. So, they tend to transmit on
top of each other. Instant collisions.

The solution is to turn on CTS/RTS flow control at the central access
point. It will slow everyone down, but it will eliminate collisions.

It's also possible that someone has messed with the timing on the
Senao card and set it for a more aggressive retry time, effectively
hogging the channel. You might wanna replace the CPE and see if it
helps.



--
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