High packet loss in netbsd-5.0 domU

[Anup Patil <anupp%gmx.net@localhost>]

On a netbsd-5.0 RC2 domU under xen-3.3.1, It was found that packet
losses were upto 50% for udp network tests. The network load was
generated using iperf and udp datagrams of length 100 to 1470 were
transmitted.


iperf output:
------------------------------------------------------------
Client connecting to 10.10.19.17, UDP port 5001
Sending 100 byte datagrams
UDP buffer size: 9.00 KByte (default)
------------------------------------------------------------
[  3] local 10.10.19.7 port 65519 connected with 10.10.19.17 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.1 sec  1.80 MBytes  1.49 Mbits/sec
[  3] Sent 18922 datagrams
[  3] Server Report:
[ ID] Interval       Transfer     Bandwidth       Jitter   Lost/Total
Datagrams
[  3]  0.0-10.1 sec    945 KBytes    763 Kbits/sec  0.049 ms 9247/18921
(49%)
[  3]  0.0-10.1 sec  1 datagrams received out-of-order


------------------------------------------------------------
Client connecting to 10.10.19.17, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 9.00 KByte (default)
------------------------------------------------------------
[  3] local 10.10.19.7 port 65520 connected with 10.10.19.17 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.1 sec  24.7 MBytes  20.6 Mbits/sec
[  3] Sent 17631 datagrams
[  3] Server Report:
[ ID] Interval       Transfer     Bandwidth       Jitter   Lost/Total
Datagrams
[  3]  0.0-10.1 sec  4.27 MBytes  3.55 Mbits/sec  0.122 ms 14586/17630
(83%)
[  3]  0.0-10.1 sec  1 datagrams received out-of-order


Any ideas where i can look further ?


--anup