If I try to upload data from my machine to anywhere, the speed is very low and the
connection gets stalled every 5seconds. Using SFTP/SCP I end up "- STALLED -"
every 5seconds, and it usually stays stalled for 5-10secs, and then It uploads 15kB
chunk and again the data transfer is stalled.
Generally the uploading speed is 2-4KB/s (way too slow + those stalls).
Same behavior happens with any other, httpd (apache) ftpd(proftpd)... no matter what I use
for transferring files out of the machine, I get the same result.

I'm running NetBSD 1.6 on i486 as a NAT-machine to share internet connection for my other
two computers.

The strange thing with this is that if I use any of those machines behind the NAT to
upload, they'll do it fine, without any of the following problems described.
The places are even the same, not to blame any network congestions.

I'm on a cablemodem with 2Mbps down and 256Kbps up.

I used to have a altqd on the machine with unsatisfying results, but I recompiled the
kernel again without enabling _any_ altq options on to kernel.
I have tried other kernel configs too (disabling BPFilter, and booting GENERIC)
with same results.

I'am really out of clues, this can't be because of altqd ghosting around,
since it doesn't work anymore when I recompiled the kernel, or? it's not Houdini, is it?!

I've tried to change these by sysctl, with no affection:

net.inet.tcp.ack_on_push 1 or 0
net.inet.tcp.rfc1323 1 or 0
net.inet.tcp.sendspace 16384 or 65536
net.inet.tcp.recvspace 16384 or 65536
net.inet.tcp.cwm 0 or 1
net.inet.tcp.cwm_burstsize 4 or 32


The downstream doesn't have any problems at all. Downloading works from the
i486-machine at full speed, as well as from the machines behind the NAT.