A customer is using io-net on 6.3.2 w. a speedo chip on an 850MHz X86.

all traffic is UDP - trying to wring every drop out - currently around 40Mps one way, 20Mbps the other. The CPU is 
pretty much maxed out.

They drop a couple of packets every 40 minutes, pretty much to the second.
They want to know if anything in the stack has a timeout of 2400s ?

I see ntp at 1200s, but nothing specifically at 2400 - any ideas ?
They wonder if it could be arp table updates and, if so, how they can disable them...

I think that if they're this maxed out, then it could be almost anything...

They've also seen this message occasionally:
tcpip: blown stack handling 0x102.  See "stacksize" option

Any ideas ?

Thanks !

Dave