How good can IP routing be
Dean H. Lorenz, Ariel Orda, Danny Raz · 2001
In the traditional IP scheme, both the packet forwarding and the routing protocols are source invariant, i.e., their decisions depend on the destination IP address and not on the source address. Recent protocols, such as MPLS, as well as traditional circuit based protocols like PNNI allow routing decisions to depend on both the source and destination addresses. In fact, much of the theoretical work on routing assumes per-flow forwarding and routing, i.e., the forwarding decision is based on both the source and destination addresses.