Patent ID: 6894978

Claim:
A method for operating a resilient closed communication network comprising at least one communication ring, the method comprising the steps of: receiving a data packet from a first external network at a first distributing station connected to the resilient closed communication network; identifying a second distributing station connected to the resilient closed communication network from which the data packet is to be forwarded to a second external network; determining functioning routes from the first distributing station to the second distributing station within the resilient closed communication network; selecting an optimal route among the functioning routes; and sending the data packet from the first distributing station to the second distributing station using the optimal route; wherein the selecting step includes the steps of: calculating an available traffic volume for each of the functioning routes; maintaining a distance table containing information necessary to determine an actual distance value for each of the functioning routes; finding optimal route candidates, which are routes with the smallest actual distance value among the functioning routes with a positive available traffic volume if at least one functioning route has a positive available traffic volume, routes with the smallest actual distance value among the functioning routes with an available traffic volume of zero if the largest available traffic volume for the functioning routes is zero, or routes with the largest available traffic volume if all the functioning routes have a negative available traffic volume; and choosing an optimal route from the optical route candidates.