OmniPeek Support

Linksys WUSB600N v2 can't scan channells between 64 and 149

ankir
Posts: 8
Joined: Wed Mar 17, 2010 1:55 am

Linksys WUSB600N v2 can't scan channells between 64 and 149

Postby ankir » Wed Mar 17, 2010 2:10 am

Hello,

I have Linksys WUSB600N v2 wireless adapter and the ralink driver for it downloaded from your site. I'm trying to do a scan on all available channels in 5GHz band, but the OmniPeek 6.0.7 scans only channels 36-64 and 149-161, which seem to relate to Country Region 0. I change the Country Region to #7 (36-165) using the driver advanced property page and restart OmniPeek, but it still can scan only channels 36-64 and 149-161. I tried doing same things in various combinations with rebooting my computer, but it did not help.

The question is: how is it possible to make Linksys WUSB600N v2 scan all the channels?

DJWP
Posts: 676
Joined: Tue Oct 30, 2007 11:42 am

RE: Linksys WUSB600N v2 can't scan channells between 64 and

Postby DJWP » Wed Mar 17, 2010 7:55 am

OmniPeek can only display the channels shown to the application by the adapter. You may want to check with Linksys for further explanation of their channel display.

ankir
Posts: 8
Joined: Wed Mar 17, 2010 1:55 am

Re: RE: Linksys WUSB600N v2 can't scan channells between 64

Postby ankir » Wed Mar 17, 2010 8:28 am

[quote="DJWP"]OmniPeek can only display the channels shown to the application by the adapter. You may want to check with Linksys for further explanation of their channel display.[/quote]
Hi DJWP, and thank you for your response. My assumption was that if I can change the available channels via the adapters' driver interface, OmniPeek should be able to read and use them. But it seems it can't. Currently I'm trying to find a workaround for this stupid behaviour and it looks like I've found one method that does what I need. I'm verifying it and will post it here if it works. But now it seems to be a problem of OmniPeek-Wlan card driver interaction.

DJWP
Posts: 676
Joined: Tue Oct 30, 2007 11:42 am

RE: Re: RE: Linksys WUSB600N v2 can't scan channells between

Postby DJWP » Wed Mar 17, 2010 9:24 am

We have seen the same behavior here with the Linksysy WUSB600N. Changing the country designation has no effect on the channels available to OmniPeek. Please let us know if you find a workaround, we would be interested to know it.

ankir
Posts: 8
Joined: Wed Mar 17, 2010 1:55 am

RE: Re: RE: Linksys WUSB600N v2 can't scan channells between

Postby ankir » Wed Mar 17, 2010 9:28 am

as promised, here is a solution that allows to scan or capture on all channels with Linksys WUSB600N v2:

1. attache your WUSB600N
2. go to Device Manager and make sure that Country Region for 5GHz is #0
3. run OmniPeek
4. Press New Capture (here I check that I can scan only channels 36-64 and 149-161)
5. Start capture
6. Stop Capture (I do it when it begins scanning channel 149 after channel 64)
7. go to Device Manager and change Country Region for 5GHz to #7 (36-165)
8. wait until Device Manager stops refreshing and Start Capture. Usually at this step OmniPeek shows an error window saying that the adapter is not available. May be I need to wait a bit longer, but I suspect it is another feature (or bug) of OmniPeek. I just press OK and Start the capture again. Voila. It scans all the channels.

If you leave Country Region for 5GHz #7, then next time you start OmniPeek you'll have to change it to #0 (or just not #7) and then to #7 again.

Probably there is another, easier sequence of actions to achieve the same result, but I hope this one can give some clue to the OmniPeek developers to fix the problem. It definitely is in OmniPeek - WUSB600N interaction.

Another problem that I ran into is that I can't capture packets transmitted using more than one spatial stream. OmniPeek displays them only occasionally. I think this problem is caused either by the Card or by its driver, but there is a minor chance that like in the case with channels it is a wrong interaction of OmniPeek with the driver. Can anyone suggest a wlan card that reliably captures MIMO packets (provided that signal is strong enough)?
Last edited by ankir on Wed Mar 17, 2010 9:40 am, edited 1 time in total.

ankir
Posts: 8
Joined: Wed Mar 17, 2010 1:55 am

RE: RE: Re: RE: Linksys WUSB600N v2 can't scan channells bet

Postby ankir » Wed Mar 17, 2010 9:38 am

One addition, my workaround does not work on my second machine. I suspect that there is a problem with how the driver or OmniPeek reads information from the registry.

On my first machine where my workaround works I've never installed for WUSB60N any Linksys original drivers. I was using there only the one downloaded from this site. Later got an updated version from Ralink web-site, but it demonstrates the same behaviour.

On my second machine I had at least a couple of different original Linksys drivers installed (along with their utilities) and only after that I installed the OmniPeek driver.

Another issue that I noticed even with the original Linksys drivers is that it depends what USB port you plug your adapter in. When I plugged it into one on the back of my desktop, Linksys' utility could not find an AP that is about 10 feet away. Then I plugged it in a port on the front and it worked just fine. Looks like a problem with enumerating USB devices...

&^#%^$%

DJWP
Posts: 676
Joined: Tue Oct 30, 2007 11:42 am

RE: RE: RE: Re: RE: Linksys WUSB600N v2 can't scan channells

Postby DJWP » Wed Mar 17, 2010 9:44 am

Thank you very much, this is helpful information. It is our experience as well that the USB interface is not really sufficient for mission critical applications.

ankir
Posts: 8
Joined: Wed Mar 17, 2010 1:55 am

Re: RE: RE: RE: Re: RE: Linksys WUSB600N v2 can't scan chann

Postby ankir » Wed Mar 17, 2010 2:43 pm

[quote="DJWP"]It is our experience as well that the USB interface is not really sufficient for mission critical applications.[/quote]

I would not say so. Yes, there may be some latency, but there should not be any problems with the bandwidth, specifically at low speed MIMO rates. With WUSB600N OmniPeek captures just fine 60 Mbps (one spatial stream) data frames, but it does not capture even 13 Mbps data frames sent via two spatial streams. By the way, I recall I had the same problem with OmniPeek and an Atheros based adapter in 2.4 GHz a couple of years ago. That time I thought it was a problem of a draft implementation of MIMO wlan cards/drivers. But why the problem has not been resolved yet after the final approval of .11n?

DJWP
Posts: 676
Joined: Tue Oct 30, 2007 11:42 am

RE: Re: RE: RE: RE: Re: RE: Linksys WUSB600N v2 can't scan c

Postby DJWP » Thu Mar 18, 2010 8:58 am

First of all, MIMO is not yet supported. Second, internal testing shows that USB adapters simply capture less packets under identical DUT than PCMCIA or PCI adapters.

We really appreciate all of your tests and input. We are working on a new version of the Atheros driver which will support more chipsets.

ankir
Posts: 8
Joined: Wed Mar 17, 2010 1:55 am

Re: RE: Re: RE: RE: RE: Re: RE: Linksys WUSB600N v2 can't sc

Postby ankir » Thu Mar 18, 2010 9:51 am

[quote="DJWP"]First of all, MIMO is not yet supported...[/quote]

What do you mean? If you support .11n radios (and WUSB600N does really support it), they do MIMO exchange by their nature. And OmniPeek does show the corresponding rates in the 'Data Rate' column. The problem is that it shows all or almost all packets transmitted at single spatial stream rates, and almost no packets at two spatial stream rates. Indeed some of them are really shown, e.g. for data rates 117 Mpbs, 130 Mbps, etc. but most often such packets are shown as having CRC error. And even then, OmniPeeks shows only very little fraction of packets transmitted at two spatial streams.
This may be a problem of the ralink driver, but as I wrote, I saw similar behaviour with an atheros miniPCI card and now I remember with Netgear WN511T too. I will try to find my WN511T to check if something has improved since that time.

[quote="DJWP"]Second, internal testing shows that USB adapters simply capture less packets under identical DUT than PCMCIA or PCI adapters.[/quote]

This may be the case, but sometimes it's enough to have even not complete capture. But anyway, my feeling is that the problem is basically caused by imperfect driver or driver -OmniPeek interaction, rather than by the USB interface. And specifically for the cases when USB bandwidth is sufficient for passing all wireless traffic (say at least up to 240 Mbps).

DJWP
Posts: 676
Joined: Tue Oct 30, 2007 11:42 am

RE: Linksys WUSB600N v2 can't sc

Postby DJWP » Thu Mar 18, 2010 2:06 pm

Thank you for your input. OmniPeek does display a single spatial stream at present.

ankir
Posts: 8
Joined: Wed Mar 17, 2010 1:55 am

Re: RE: Linksys WUSB600N v2 can't sc

Postby ankir » Thu Mar 18, 2010 2:13 pm

[quote="DJWP"]...OmniPeek does display a single spatial stream at present.[/quote]

Is there any explanation why it can not display two spatial stream packets?
In fact, as I wrote above, it does display some of two spatial stream packets too, but only occasionally. And I can't understand WHY it happens, because they are definitely received and decoded by the card, and there is no reason not to pass them up the stack where OmniPeek may get and display them. May OmniPeek filter them out as incorrectly formatted ones?

DJWP
Posts: 676
Joined: Tue Oct 30, 2007 11:42 am

RE: Re: RE: Linksys WUSB600N v2 can't sc

Postby DJWP » Thu Mar 18, 2010 3:22 pm

At this point, we would encourage you to bring your issue to our tech support group. Here is the link to submit a request:

http://www.wildpackets.com/support/contact

ankir
Posts: 8
Joined: Wed Mar 17, 2010 1:55 am

Re: RE: Re: RE: Linksys WUSB600N v2 can't sc

Postby ankir » Thu Mar 18, 2010 3:27 pm

[quote="DJWP"]At this point, we would encourage you to bring your issue to our tech support group. Here is the link to submit a request:

http://www.wildpackets.com/support/contact[/quote]

OK. I'm your legal customer, and I'm interested in getting any possible support with this issue. Meanwhile we can go on our discussion here if you are interested in getting any additional information.


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