Re: Traffic Engineering (fwd)

[jon () branch net (Jon Zeeff)]

The biggest drawback we saw when we evaluated this approach (way back when)
was that it depends on routing protocols, which are quite inadequate for
predicting what a user is going to experience as the "best site".  You
also create some amount (perhaps not significant) of problems for
stateful sessions (like web servers that are tracking who the user is
through their entire session).

I agree that it might be adequate for simply reducing backbone
traffic.  I believe AGIS uses this approach for their coolocation.

> > P.S.: Curtis Villamizar had another interesting approach
> >       which involved pushing content far afield to
> >       machines with the same transport-layer (IP)
> >       addresses, relying upon closest-exit routing to 
> >       connect one to the topologically-closest replication
> >       machine.  Unfortunately, while this could be really
> >       cool for NSPs to offload stuff towards peering
> >       points (public or private), it also has some poor
> >       scaling properties and is uncomfortably reliant
> >       upon the stability of routing.