fixed TX rates for broadcast messages
Markus Jakob (EEI)
Markus.Jakob at eei.ericsson.se
Thu Jan 10 03:49:55 EST 2002
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
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?
> -----Original Message-----
> From: Markus Jakob (EEI)
> Sent: Friday, January 04, 2002 5:05 PM
> To: 'wireless at lists.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
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