...

The PathControl product does *not* add routes to anyone's table; it merely provides multihomed "leaf AS's" the ability to make informed decisions about how to use the routes that their service providers give to them.

So it can only optimize outbound traffic?

not nec'ily "traffic". but anything which optimizes the outbound route chosen by tcp segments has the potential to increase the performance of both the outbound tcp flow and the symmetrical inbound tcp flow.

Hmm... Sometimes that can be useful, too.

as i indicated back in 1997 at ftp://ftp.vix.com/pub/vixie/ifdefault/: @Overhead @Title { Outbound Route Balancing } @Begin @List @LI { @S{TCP} is @S{ACK}-timed @Eq{arrowright} path symmetry is good. } @LI { Symmetry in the intermediate system is really hard. } @LI { First hop symmetry is most of what you want anyway. } @LI { @S{BGP} path selection is hard to defeat. } @EndList @End @Overhead