Pseudo-node Reduction on Multi-access Networks for Algorithmic Simplification

Link-state Internet routing protocols such as OSPF and IS-IS currently implement extra nodes called pseudo-nodes in their link-state databases to represent networks. This letter studies the effect that this has on the run-time of Dijkstra's algorithm which is implemented alongside these protocols, and analytically determines a crossover point for the number of routers per network below which pseudo-nodes do not improve the efficiency of routing calculations. The results suggest that pseudo-nodes are not necessary or desirable for any practical network with a mean of less than six routers per Ethernet, contradicting popular belief.