still puzzled by Netstumbler results

I'm using a Netgear MR814v2 router and a Zonet ZEW2501 client and with
Netstumbler I see numerous dropouts where the received signal level
goes from -45 dB to -85 dB for a few seconds. This repeats, but not
perfectly periodically, about every 5 to 10 seconds. However, the
connection works fine when I connect wirelessly to the net and run a
speed test on dslreports. I get 5 Mbps download speed without any
apparent pauses.

I tried moving the client around while running Netstumbler. No
difference. I also flashed the router to the latest firmware. No
difference. I tried using another channel. No difference.

I have another identical Netgear MR814v2 router that doesn't show the
dropouts. But both routers seem to work fine.

Anyone have an idea on why Netstumbler would show dropouts every few
seconds for one router and not the other?

Thanks,
Bruce

On Wed, 19 Oct 2005 11:27:20 -0400, bjs555 <aaa@bbb.com> wrote:

>I'm using a Netgear MR814v2 router and a Zonet ZEW2501 client and with
>Netstumbler I see numerous dropouts where the received signal level
>goes from -45 dB to -85 dB for a few seconds. This repeats, but not
>perfectly periodically, about every 5 to 10 seconds. However, the
>connection works fine when I connect wirelessly to the net and run a
>speed test on dslreports. I get 5 Mbps download speed without any
>apparent pauses.
>
>I tried moving the client around while running Netstumbler. No
>difference. I also flashed the router to the latest firmware. No
>difference. I tried using another channel. No difference.
>
>I have another identical Netgear MR814v2 router that doesn't show the
>dropouts. But both routers seem to work fine.
>
>Anyone have an idea on why Netstumbler would show dropouts every few
>seconds for one router and not the other?
>
>Thanks,
>Bruce

Well, no replies to this post so I guess I'll reply to myself. Fewer
arguments that way :) And maybe the monologue will help someone else.

What seems to determine whether there are gaps in the Netstumbler
graphs is whether or not I am broadcasting my SSID. I get the gaps
when I turn SSID broadcast off and they disappear almost entirely when
I turn SSID broadcast on. It looks like Netstumbler has trouble
recognizing the return signal from its probes when SSID is off. Or
maybe it has something to do with my setup. Has anyone else seen this
happening? Is this normal behavior for Netstumbler?

Thanks,
Bruce

Den Wed, 19 Oct 2005 14:33:18 -0400. skrev bjs555:

> On Wed, 19 Oct 2005 11:27:20 -0400, bjs555 <aaa@bbb.com> wrote:
>
>>I'm using a Netgear MR814v2 router and a Zonet ZEW2501 client and with
>>Netstumbler I see numerous dropouts where the received signal level
>>goes from -45 dB to -85 dB for a few seconds. This repeats, but not
>>perfectly periodically, about every 5 to 10 seconds. However, the
>>connection works fine when I connect wirelessly to the net and run a
>>speed test on dslreports. I get 5 Mbps download speed without any
>>apparent pauses.
>>
>>I tried moving the client around while running Netstumbler. No
>>difference. I also flashed the router to the latest firmware. No
>>difference. I tried using another channel. No difference.
>>
>>I have another identical Netgear MR814v2 router that doesn't show the
>>dropouts. But both routers seem to work fine.
>>
>>Anyone have an idea on why Netstumbler would show dropouts every few
>>seconds for one router and not the other?
>>
>>Thanks,
>>Bruce
>
> Well, no replies to this post so I guess I'll reply to myself. Fewer
> arguments that way :) And maybe the monologue will help someone else.
>
> What seems to determine whether there are gaps in the Netstumbler
> graphs is whether or not I am broadcasting my SSID. I get the gaps
> when I turn SSID broadcast off and they disappear almost entirely when
> I turn SSID broadcast on. It looks like Netstumbler has trouble
> recognizing the return signal from its probes when SSID is off. Or
> maybe it has something to do with my setup. Has anyone else seen this
> happening? Is this normal behavior for Netstumbler?
>
> Thanks,
> Bruce

Yes, because :

A) You didn't read the included documentation, if you had done so, you'd
seen that NetStumbler doesn't detect AP's with disabled SSID broadcast.

B) You didn't read the included documentation,if you had done so, you'd
seen that NetStumbler isn't designed to be used while connected to an AP.

C) You didn't read the included documentation, if you had done so, You'd
know that correct signal and noise readings are only available with cards
based on the HermesI chipset, i.e. Lucent/Agere/Proxim ORiNOCO Classic
cards, and rebadges thereof.

No prizes for guessing what you should do now.. But it involves the
included documentation.

e-teori

>> What seems to determine whether there are gaps in the Netstumbler
>> graphs is whether or not I am broadcasting my SSID. I get the gaps
>> when I turn SSID broadcast off and they disappear almost entirely when
>> I turn SSID broadcast on. It looks like Netstumbler has trouble
>> recognizing the return signal from its probes when SSID is off. Or
>> maybe it has something to do with my setup. Has anyone else seen this
>> happening? Is this normal behavior for Netstumbler?
>>
>> Thanks,
>> Bruce
>
>Yes, because :
>
>A) You didn't read the included documentation, if you had done so, you'd
>seen that NetStumbler doesn't detect AP's with disabled SSID broadcast.

The documentation that came with the version I'm using doesn't seem to
say this. From the mini-faq:

Q2. Why doesn't NetStumbler see the access point right next to my
machine?
A2A. The access point is configured not to respond to broadcast
probes. Most manufacturers call this "disable broadcast SSID" or
"closed". NetStumbler cannot see these networks unless you know the
SSID and have your machine configured to connect to it.
A2B. Your wireless card is configured to connect to a specific SSID.
Try setting it to connect to a blank SSID or to "ANY" (without
quotes).

I knew the SSID and had my machine configured to connect to it.
Netstumbler seems to see my access point ok.

>B) You didn't read the included documentation,if you had done so, you'd
>seen that NetStumbler isn't designed to be used while connected to an AP.

I don't get what you mean here.

>C) You didn't read the included documentation, if you had done so, You'd
>know that correct signal and noise readings are only available with cards
>based on the HermesI chipset, i.e. Lucent/Agere/Proxim ORiNOCO Classic
>cards, and rebadges thereof.

From the Help file:
The requirements for NetStumbler are somewhat complex and depend on
hardware, firmware versions, driver versions and operating system. The
best way to see if it works on your system is to try it.

List of some compatible hardware:
http://www.stumbler.net/compat/

The client dongle I'm using has a Zydas chip in it. I saw a reference
to Zydas in the list above so I think it meets the requirements.

The odd thing about my problem is not that Netstumbler doesn't work.
Rather, it's that it partially works when I have SSID broadcast turned
off. I suppose the thing to do is turn off SSID broadcast during
tests, but I was hoping for some insight on why Netstumbler almost
works with SSID broadcast off.

Oops, typo -
turn on SSID broadcast durning tests