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Emulation problems



Hello,

I'm trying to use the NS emulator (nse) to evaluate the performance of
different adaptive transmission schemes in a UDP/IP-based
transmitter/receiver application pair, where data is sent in "layers" on
separate ports. The nse host (a P3-550/FreeBSD 3.4 machine) serves as a
gateway between the transmitter net and the receiver net.

Things work reasonably well (although I do get an occasional "scheduler
going backwards") until after a few minutes of emulation when everything
breaks down. I get constant "going backwards" messages, mixed by
"TapAgent(): sendpkt: No buffer space available"... and the receiver 
experience massive packetloss and jitter values.

Strangely enough, things often calm down again after a few more
minutes, and suddenly there is enough buffer space again.

How can I resolve this problem? Can the buffer space be increased in 
some way?

Thanks in advance,

/Daniel F.