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From: Markus Jakob (EEI) (Markus.Jakobeei.ericsson.se)
Date: Wed Jan 09 2002 - 10:49:55 CST

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    Hi,
    it's me once more. I did some more testing on the
    problem I posted last week. It seems to be more a
    problem of fixed bit rates for broadcast messages for
    the ELSA MC-11 card why the ranges differ.

    I measured available bit rates between two nodes
    for broadcast and unicast messages.

    I run a simple application on one node which sends packets
    of a selected bitrate out to specified IP-address.
    On a second node, placed directly beside, an application
    checked the amount of received packets.

    For the Elsa Airlancer MC11 card I could see that independant of
    the TX bitrate set via iwconfig the broadcast messages
    (sending to IP-address 255.255.255.255) are sent out with the
    same bit rate. (I could never record more than around 1600kb/s
    on the second node.)
    If I have sent directly to the address of node 2 the transmission rate
    could be increased according to the rate set with iwconfig.
    (1600kb/s for 2Mb/s, 3200kb/s for 5Mb/s,...)

    Could this explain why I got different ranges for broadcast and unicast
    messages, because I had set the card to 11Mb/s but the broadcast
    messages were always transmitted with lower rate and therefore
    better coded?

    With a netgear MA401 card the rates are the same for broadcast and unicast
    using the same driver.

    Is it possible to influence this behaviour in the driver or is it a pure firmware
    or hardware problem for the ELSA cards?

    Thanks

    Markus

    > -----Original Message-----
    > From: Markus Jakob (EEI)
    > Sent: Friday, January 04, 2002 5:05 PM
    > To: 'wirelesslists.samba.org'
    > Subject: range differencies
    >
    > Hi all,
    >
    > I try to get routing protocols on an adhoc network running,
    > using ELSA airlancer cards and the orinoco driver
    > (kernel version 2.4.9, driver version 0.06f).
    > I experienced that broadcast messages have
    > bigger ranges than unicast messages sent to a
    > particular IP and MAC address, e.g at certain distances
    > between two nodes it is possible to receive a broadcast
    > messages from the other node but ping doesn't work
    > anymore between the nodes.
    > Is this a normal behaviour or is it somehow possible
    > to influence it to get the same ranges for all types of
    > messages?
    >
    > Thanks
    >
    > Markus
    >
    >
    >