Occasionally, someone fires up a P2P application and the sudden flood of
upload traffic increases the latency for download traffic (I assume as
upload becomes saturated, the ACK's for download traffic don't get out
fast enough).
Is there some kind of traffic shaping software (preferably freeware)
that I can use to throttle my upstream traffic and bring things to a
sensible compromise?
If you're ready to switch to *BSD, I'd recommend altq, as has been mentioned by other, which works well for me on NetBSD.
If you want to stay with Solaris, QoS has been included in Solaris 9 since the 9/02 release, on both Sparc and x86 (the documentation is sometimes unclear about that, but it's been confirmed by people from Sun that it works on both architectures).
http://docs.sun.com/db/doc/816-5223/6mbco0a1l?q=ipqos&a=view http://docs.sun.com/db/doc/816-4094
I've not tried it yet, though, so I can't tell you if/how well it works with ipfilter.
HTH,
Laurent
