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Wrong RSSI and Rate values RRS feed

  • Question

  • Hello! I am using a Asus WL-167G USB 2.0 WLAN Adapter card (rt73 chipset) to connect wirelessly to an Linksys AP. I have installed Microsoft Network Monitor 3.4 version. I would like to do a simple monitoring of the network (locally i.e. not in promiscuous mode) and compare with Wireshark results from a third party Linux pc in promiscuous mode. My concern regards the WiFi.MetaData. information, and particularly the RSSI and rate metrics. From the NM3.4 software, using the above mentioned card, the RSSI and rate values are "stuck" at -50dBm and 3.5 mbps respectively. On, the other hand Wireshark shows more realistic values (ie I was expecting data rate to be more than 11 Mbps) that vary slightly with each frame. Is there something wrong with the driver ? Should I test another wireless card ? Do you have any suggestions ?

    Kind regards


    • Edited by Costas7 Wednesday, September 28, 2011 2:46 PM
    Wednesday, September 28, 2011 1:14 PM

All replies

  • I do remember one bug with our parsers, though I'm not certain it would adress this specific problem.  Are you using the latest parsers from http://nmparsers.codeplex.com/?

     

    Thanks,

    Paul


    Wednesday, September 28, 2011 1:54 PM
  • Hello,

    Thanks for the fast reply. I did download and install the latest parsers for my system (64 bit) but this did not fix the problem ... I have set up the Access Point (AP) to transmitt at 1Mbps but still NM3.4 reports 3.5 Mbps for frames sent by the AP. Also when being used in monitor mode to monitor another laptop (client) associated to the AP, the RSSI and Rate do not change when increasing the distance between the client and the AP.

    Do you have any other suggestions ?

    Wednesday, September 28, 2011 2:48 PM
  • I suppose at this point it would be helpful to see a trace.  Can you share one for me, perhaps on skydrive or something similar?

     

    Thanks,

    Paul

    Wednesday, October 5, 2011 2:29 PM
  • Hello

    Sorry for the delay. I attach a link to a .cap file. I did a simple experiment of sending about 50 pings from the client (using the above mentioned Asus card) to the AP. The file is 111KB.

    Since last time I have realised that this issue is related to this particular chipset (rt73). Other cards (like Atheros chipsets) do not exhibit this problem and show correct RSSI and rate values. 

    Thank you

     

    http://www.filesonic.com/file/2683107011/50_pings_using_rt73_chipset_card.cap
    Friday, October 21, 2011 1:52 PM
  • We depend on the driver to return this information to NDIS, which is where we get the data that appears in the trace.  It appears this manufacture did not report the information accurately to NDIS. 

    Thanks,

    Paul

    Monday, October 24, 2011 9:22 PM