mysterious wireless problem

I have a d-link 802.11g wireless access point. It has two big
antenaes. Across the room is a linksys 54g wireless pci board. It
also has a big antennae. Throughout the house are scattered other
wireless things like a tivo downstairs and a couple other computers.
Most times, things work, although I only get 83% signal strength from
15 feet away. Sometimes though, the wireless network goes down. When
this happens, my network disappears from the list when I browse for
networks, and sometimes reappears breifly, but does not allow
connections. This is exceptionally annoying.

There are a lot of wireless networks in the list, like a dozen or so.

I'm using 128 bit wep as is everyone else.

I've tried three different access points. All showed identical
behavior.

All the machines go down at once.

Changing the channel has no affect.

Can anyone suggest what might be happening and how to fix it? My gut
is telling me that there are so many networks that we're stepping on
each other, or that someone has a cordless phone or something that
happens to occupy the same frequency band.

brian

(E-Mail Removed) hath wroth:

>I have a d-link 802.11g wireless access point.

Model number? Hardware version? Firmware version?

>It has two big
>antenaes.

How many inches or cm do you consider big?

>Across the room is a linksys 54g wireless pci board.

Model number? Hardware version? Driver version? Windoze version?

>It
>also has a big antennae. Throughout the house are scattered other
>wireless things like a tivo downstairs and a couple other computers.
>Most times, things work, although I only get 83% signal strength from
>15 feet away.

Is the 15ft line of sight or is there furniture in the way? Can you
see the "big" antenna sticking out of the Wireless PCI board or is it
buried behind a steel box amid a mess of wires and cables? 83% seems
only a little bit too low. It should be about 90% especially with
"big" antennas. However, the detector that outputs RSSI is not
terribly accurate and rarely gets to 100%. It saturates at perhaps
90% on most devices I've tinkered with.

>Sometimes though, the wireless network goes down.

How often does it disappear and for how long? This is not a trivial
question. If it follows a pattern, it will help identify a possible
source of interference such as 2.4GHz cordless phones, microwave
ovens, and other wireless networks. Do you have any other 2.4GHz
wireless devices in the area?

>When
>this happens, my network disappears from the list when I browse for
>networks, and sometimes reappears breifly, but does not allow
>connections. This is exceptionally annoying.

What happens when you wiggle the "big" antennas? Could be a loose or
broken antenna.

>There are a lot of wireless networks in the list, like a dozen or so.

What list? Windoze Wireless Zero config or the Linksys PCI card
driver utility? Are they currently available networks or just
leftovers from previous connections? If you're not sure, flush the
list of anything you don't need and see if the re-appear.

>I'm using 128 bit wep as is everyone else.

I'm using WPA. It's much more secure than WEP.

>I've tried three different access points. All showed identical
>behavior.

Did you use the same "big" antennas? What else didn't change? If
the access point is NOT the problem, that leaves your wireless PCI
card. Check the web pile for driver updates. The relatively low
signal strength makes me wonder if the card or antenna connector isn't
broken. However, this is unlikely.

>All the machines go down at once.

Bingo. Interference, probably at the access point. Do you have it
located in a window where it can see the crud from the rest of the
neighborhood? If so, move it behind a wall. Try a different RF
channel (1, 6, or 11). Look around for interference sources.

>Changing the channel has no affect.

If it is inteference, then it's not coming from another wireless
network. That leaves cordless phones, microwave ovens, industrial
dryers, video links, and frequeny hopping devices.

>Can anyone suggest what might be happening and how to fix it? My gut
>is telling me that there are so many networks that we're stepping on
>each other, or that someone has a cordless phone or something that
>happens to occupy the same frequency band.

Dunno. Spectrum analyzer?
http://www.metageek.net

Do you have any control over the other Wi-Fi devices? If so, unplug
or disarm and run a test to see if there's one particular device
that's causing problems. Definately try moving the access point to a
more "protected" location.

>brian
--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

It's this one:

http://www.bestbuy.com/site/olspage....=1125465404397

But I've tried another d-link and a linksys router and all behaved
exactly the same way.

The card is a linksys wmp54g. I'm using xp, but I can't remember the
service pack level off hand. All of the machines in the house are xp.
They have different boards (mostly netgear), all go down including the
tivo.

>Is the 15ft line of sight or is there furniture in the way?

Line of sight.


>How often does it disappear and for how long? This is not a trivial
>question. If it follows a pattern, it will help identify a possible
>source of interference such as 2.4GHz cordless phones, microwave
>ovens, and other wireless networks. Do you have any other 2.4GHz
>wireless devices in the area?

It goes down maybe twice a week. When it happens during the day, my
wife gives up on it. Then when I get home, I disable/enable and it
comes right back up. Other times when it happens, there's nothing to
connect to since it doesn't show up in the list. I just keep hitting
refresh. Sometimes it comes back, sometimes not.

It's probably not the microwave since we use that a lot more than it
goes down. We have a cordless phone, but iirc, it's not 2.4ghz. And
using or not using the phone doesn't seem to have an affect. There's
no other wireless devices in our house. If there is interference, it's
not from us.

Moving the antenae has no affect, nor does changing the channel.

>Bingo. Interference, probably at the access point. Do you have it
>located in a window where it can see the crud from the rest of the
>neighborhood?

No, it's accross the room on a book case. Although it still manages to
pick up *a lot* of other networks when it's working. Like 10-12 other
networks. When it goes down, I can see 2 or 3, none of them mine.

>That leaves cordless phones,

Would the neighbor's phone be close enough for this? it's a tract
neighborhood with maybe 20 feet between the houses.

>microwave ovens,

same thing. it's not ours.

>industrial
>dryers,

like in a laudromat? we don't have any. And our dryer is gas-powered
and runs constantly.

>video links,

like a wireless security camera? I don't have anything like that.
maybe the neighbors do.

>and frequeny hopping devices.

I'm not sure what this would be. Car transmitters or garage door
openers? Those work in bursts. I would think they could knock me off,
then I could get back on. Sometimes, I'm kept off for 20 minutes or
more.

>Definately try moving the access point to a
>more "protected" location.

I'm not sure where I would put it.

The guy at besy buy (yuk) suggested switching to a different "country"
that has channels other than 1-11. My card supports this, but it looks
like the access point doesn't.

It's been behaving lately, but now comcast is flaky. I'll see if I can
gather more intel next time it goes down.

brian

On 21 Mar 2006 15:21:28 -0800, (E-Mail Removed) wrote:

>It's this one:
>http://www.bestbuy.com/site/olspage....=1125465404397

Dlink DI-634M MIMO wireless router. The one my customer bought had
version 2.00 firmware. I had to update it to 2.01 to get it to stay
connected for more than 10 minutes.
http://support.dlink.com/products/vi...ctid=DI%2D634M
I'm not sure if this has anything to do with your problem. Probably
not but worth checking the firmware version.

>All of the machines in the house are xp.
>They have different boards (mostly netgear), all go down including the
>tivo.

If that's true, and it is interference, then it's happening at the
DI-634M end. Do something to protect the router from interference.
Instead of the bookshelf, move it down to the floor temporarily.

>It goes down maybe twice a week.

Reading between the lines, when it does down, it stays down for 10-20
minutes. Is this correct?

>When it happens during the day, my
>wife gives up on it. Then when I get home, I disable/enable and it
>comes right back up.

So, it does NOT come back by itself. If the connection is dropped for
less than about 60 seconds (or so), then the client should reconnect
automagically. However, interruptions of longer than about a minute
will initiate a disconnect and the client will need to manually
reconnect. There should be a setting in XP Wireless Zero Config that
allows for additional persistance and automatic reconnect. Same with
the Linksys WMP54G driver program. I don't have either running in
front of me and therefore can't supply the exact location of the
setting. Something like "preferred network SSID" and "connect
automatically".

>Other times when it happens, there's nothing to
>connect to since it doesn't show up in the list. I just keep hitting
>refresh. Sometimes it comes back, sometimes not.

Are you beaconing your SSID? I presume so since you're trying to
refresh the list of SSID's. However, if you installed the SSID in the
clients connection profile, it might not find it. I don't think this
is the problem but if you happen to have SSID broadcast disabled, try
turning it on and see if it recovers more gracefully.

Also, the Super-G and Turbo-G products have problems making connection
to ordinary clients. If you're not using Super-G or "dynamic turbo",
try turning them both off:
http://support.dlink.com/Emulators/d...eless_11g.html

>It's probably not the microwave since we use that a lot more than it
>goes down. We have a cordless phone, but iirc, it's not 2.4ghz. And
>using or not using the phone doesn't seem to have an affect. There's
>no other wireless devices in our house. If there is interference, it's
>not from us.

Think of the pattern. Once or twice a week for periods lasting a few
minutes with fairly high power levels. That's not something that's
very common. Frankly, I don't have a clue. Instead of trying to
identify the source, methinks the best strategy would be to protect
the router and to do whatever is necessary to help the client recover
more quickly.

Checklist of possible interference sources:
Microwave oven
2.4Ghz video or security camera link (X10).
Municipal wireless networks.
Bluetooth devices (mouse, phone, PDA, headset, cell phone, etc)
Portable wireless TV camera used at sports events.
Frequency hopping cordless phones (Panasonic Gigarange)
802.11b/g wireless keyboards, PDA's, and cell phones.
2.4GHz game pads and controllers.
RF Excited Lighting (Fusion Lighting).
2.4GHz baby monitors.
2.4GHz ham radio operation.
WISP (wireless internet service providers) which may be using
non-802.11 type of modulation (i.e. WiMax).
Breezecom/Alvarion/Symbol/Raylink frequency hopping networks.
Western Multiplex or Proxim non-802.11 wireless links. (e.g Lynx).
HomeRF frequency hopping network.
Zigbee 802.15.4 sensor wireless network.
Microwave fruit drying oven, plastic mold preheater.
Unstable high power wi-fi power amplifier spraying garbage.

>Moving the antenae has no affect, nor does changing the channel.

If it takes a week for it to happen, how many changes have you made or
tried? I didn't say move the antenna. I said move the entire access
point with the antenna to some place that is less susceptable to
outside interference.

>No, it's accross the room on a book case. Although it still manages to
>pick up *a lot* of other networks when it's working. Like 10-12 other
>networks. When it goes down, I can see 2 or 3, none of them mine.

So, when the alleged interference is present, you can only see 2-3
networks. That's possible if the interference is very strong. The
only thing that can cause literally everything to go deaf
simultaneously is a very strong source of RF interference.

>Would the neighbor's phone be close enough for this? it's a tract
>neighborhood with maybe 20 feet between the houses.

No. Too low power, too far away, wrong interference pattern.

>>industrial
>>dryers,
>
>like in a laudromat? we don't have any. And our dryer is gas-powered
>and runs constantly.

No. Any manufactory that needs to remove water from something might
have a microwave drier. Fruit driers, plastic injection molding
pre-heaters, flash pasturizers, etc. Got any industry nearby?

>like a wireless security camera? I don't have anything like that.
>maybe the neighbors do.

That's a possible. Some video links are rather high power and are run
by motion detectors or alarms. The only way you're going to see one
is with a spectrum analyzer. Also, TV stations use 2.4GHz on some of
their wireless cameras. These run rather high power (up to 10 watts).
Any nearby TV studios?

>>and frequeny hopping devices.
>
>I'm not sure what this would be. Car transmitters or garage door
>openers? Those work in bursts. I would think they could knock me off,
>then I could get back on. Sometimes, I'm kept off for 20 minutes or
>more.

No. FHSS are some cordless phones, Alvarion/Breezecom radios,
Bluetooth, Proxim radios, HomeRF networks, and other devices. None of
these fit the interference pattern.

>>Definately try moving the access point to a
>>more "protected" location.
>
>I'm not sure where I would put it.

At the end of a CAT5 extension cord. Use your imagination.

>The guy at besy buy (yuk) suggested switching to a different "country"
>that has channels other than 1-11. My card supports this, but it looks
>like the access point doesn't.

Tell him I'll be happy to turn him in to the FCC (if they offer a
suitable bounty or reward) for illegal modifications to wireless
equipment. The frequencies above CH11 are used by satellite mobile
downlinks. I'm sure they'll be thrilled.

>It's been behaving lately, but now comcast is flaky. I'll see if I can
>gather more intel next time it goes down.

Get the signal strength and noise level numbers from the WMP54G for
normal and when interference is present.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 (E-Mail Removed)
# http://802.11junk.com (E-Mail Removed)
# http://www.LearnByDestroying.com AE6KS

In article <(E-Mail Removed) .com>,
(E-Mail Removed) says...
> I have a d-link 802.11g wireless access point. It has two big
> antenaes. Across the room is a linksys 54g wireless pci board. It
> also has a big antennae. Throughout the house are scattered other
> wireless things like a tivo downstairs and a couple other computers.
> Most times, things work, although I only get 83% signal strength from
> 15 feet away. Sometimes though, the wireless network goes down. When
> this happens, my network disappears from the list when I browse for
> networks, and sometimes reappears breifly, but does not allow
> connections. This is exceptionally annoying.
>
> There are a lot of wireless networks in the list, like a dozen or so.
>
> I'm using 128 bit wep as is everyone else.
>
> I've tried three different access points. All showed identical
> behavior.
>
> All the machines go down at once.
>
> Changing the channel has no affect.
>
> Can anyone suggest what might be happening and how to fix it? My gut
> is telling me that there are so many networks that we're stepping on
> each other, or that someone has a cordless phone or something that
> happens to occupy the same frequency band.
>
> brian
>
>
have you tried a different connection to your computer? For example, in
a relatively low signal area of my house, my Thinkpad drops it's signal
very frequently. But, in the same area, if I use a good Linksys PC
card, the connection is held and signals don't drop.

Louise