pf's "borrow" equivalent

[eternityos at free.fr]

Hi everyone,

I'm new to this list, I use ipfw+dummynet for traffic shaping.
I'm having an issue...
I have two users that share a same pipe of 128Kbit/s, so when a user is
not using internet, the other gets 128KBit/s.

Now my issue is, when both users use internet at the same time, let's say
user A is using a P2P software and user B simply surfing the web.

Logicaly, user A is taking the whole bandwidth and user B is having issues
surfing.

I want to guarantee at least 64K, so user A will have at least 64K when using
internet.

I already asked about this in #freebsd channel in freenode.... and I been
answered
"use pf's borrow option".

So, is there a pf's borrow option equivalent in pf or any other way to deal with
this issue ?

Thanks in advance :)

Pierre.