What's Next?

In the real world, intra-domain Internet routing uses either link-state (for larger domains) or distance vector (for smaller domains) approaches. Inter-domain routing involves issues like policy routing (eg: restrictions on the paths which can be used by certain subsets of nodes, what they pay to use it, and what quality of service they get, etc.), which invalidates metric assumptions in both distance-vector and link-state routing. This is a tough problem being tackled by researchers today.

Topology design is another area of networking which is graph-theoretic in nature. Such a problem includes specifications of connectivity, network cost, routing stability and flexibility, reliability and availability. A network topology adhering to given parameters is best modeled and analyzed in terms of graph theory.