ng_one2many - very slow

donatas donatas at lrtc.net
Fri Sep 17 03:17:13 PDT 2004


Hello,

we need a 400Mbit link between two intel machines (Xeon 2.4, Raid, 512DDr, 2 ports-em(1000Mbit),2 ports-fxp(100Mbit))

configuration taken from ng_one2many man page:
_____________________________________________________________________
ifconfig em0 up media 100BaseTX mediaopt full-duplex
ifconfig em1 up media 100BaseTX mediaopt full-duplex
ifconfig fxp0 up media 100BaseTX mediaopt full-duplex
ifconfig fxp1 up media 100BaseTX mediaopt full-duplex

ngctl mkpeer em0: one2many upper one
       ngctl connect em0: em0:upper lower many0
       ngctl connect em1: em0:upper lower many1
       ngctl connect fxp0: em0:upper lower many2
       ngctl connect fxp1: em0:upper lower many3
       ngctl msg em1: setpromisc 1
       ngctl msg fxp0: setpromisc 1
       ngctl msg fxp1: setpromisc 1
       ngctl msg em1: setautosrc 0
       ngctl msg fxp0: setautosrc 0
       ngctl msg fxp1: setautosrc 0
       ngctl msg em0:upper setconfig "{ xmitAlg=1 failAlg=1 enabledLinks=[ 1 1 1 1 ] }"
       ifconfig em0 192.168.1.1/24 (and 1.2/24 on the second machine)
_______________________________________________________________________
kernel is compiled with the following options:
NETGRAPH
NETGRAPH_BRIDGE
NETGRAPH_ECHO
NETGRAPH_ETHER
NETGRAPH_FACE
NETGRAPH_ONE2MANY
________________________________________________________________________
OS - FreeBSD  5.2.1 - freshly installed
machines are connected directly(port -to- port) with crossed UTP CAT5 cables
________________________________________________________________________
we used iperf to test TCP throughput between those machines:
Results:
10sec.    Transfered 250MBytes        Bandwidth 210Mbits/sec        -in simplex mode

and in duplex mode:
10sec.    Transfered 169MBytes        Bandwidth 141Mbits/sec
10sec.    Transfered 163MBytes        Bandwidth 136Mbits/sec

after changing "enabledLinks=[1 1 1 1] to [1 1] the results are allmost the same:
________________________________________________________________________
10sec.    Transfered 242MBytes        Bandwidth 203Mbits/sec        -in simplex mode

and in duplex mode:
10sec.    Transfered 163MBytes        Bandwidth 136Mbits/sec
10sec.    Transfered 150MBytes        Bandwidth 125Mbits/sec
________________________________________________________________________
60 second transfer indicated 223Mbits/sec in simplex mode

truth, we've tested direct link between em adapters in gigabit mode and using TCP packets 850Mbit throughput was achieved. And Nearly 1Gbit with UDP packets.

as you see one2many test results aren't even close to 400Mbit
Is it possible that em and fxp cannot work together or something. what can you suggest to solve this small problem?

thanks in advance


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