msg lost between sendto() and nettl traces

[BERTRAND_7]

Hello,

We currently face some lost messages.
We are running HPUX 11iv3 + March 2009 bundles.
We use one lan (lan2) managed by 'iether' driver.

In our application we send some messages in UDP using the 'sendto()' function. The function always return the number of bytes equal to number of bytes provided in the buffer. So we assume there's no error to send the message.

Yet, after activating the nttl traces, we observe that some messages of our application do not appear in the trace file.

We have :
netstat -in
lan2 10.1.100.100 MTU 1500 Ierrs=0 Oerrs=0

lanadmin -x 2
Speed = 100 Full-Duplex
Autonegotiation=On

lanadmin -g mibstats 2
Inbound erros = 0
Outbounds errors = 0


As we are connected to an industrial network, it is normal that with communicate at 100 Full-Duplex since the switch doesn't support 1Gb.

Where could be the problem ?
- in the sendto function ?
- in the iether driver ?

Any suggestion is welcome.

Bruno