Capex comparison between link-by-link and end-to-end grooming in a European backbone network

This paper compares the traditional link-by-link traffic grooming approach to the end-to-end grooming solution where OXCs are present in all network nodes. The comparison is made based on the difference in expected capital expenditures between both approaches. We indicate that, as traffic grows, there comes a point where the savings in IP layer expenses realized by end-to-end grooming compensate the extra expenses of introducing the needed optical cross connects. This cost intersection point is determined in a realistic case, considering a European backbone network with fast growing traffic. The impact of different component cost ratios and cost evolutions on this intersection point is studied. This point is shown to be most sensitive to a changing SDH card cost. Using realistic cost figures for the considered network components, which are decreasing over time, we expect the end-to-end grooming approach to become more economical than link-by-link grooming for the studied European backbone by the end of 2005.