Reducing Costs in IP Networks with OTN Transport Efficiency: An Empirical Analysis of CAPEX/OPEX Optimization

We present a large-scale empirical evaluation of Optical Transport Network (OTN) as a cost-optimization strategy for IP transport infrastructures.Using operational and cost data from 12 operators, 45 transport platforms, and 12 representative network scenarios, we compare OTN with legacy SDH/DWDM across metro, regional, long-haul, and international backbones.A hypothesis-driven framework-combining bottom-up cost modeling, paired t-tests/ANOVA, regression, and Monte Carlo sensitivity analysis-quantifies impacts on CAPEX, OPEX, energy, bandwidth efficiency, and scale economics.Results show statistically significant reductions of 35-40% in CAPEX and 33-42% in OPEX (p < 0.001), driven by wavelength reduction via sub-wavelength grooming, improved bandwidth utilization (~40%), equipment consolidation, and superior energy efficiency.Power per transported gigabit falls by 46-52%, accounting for nearly half of OPEX savings.Economies of scale are evident: cost advantages rise from ~30% at 100 Gbps to >40% in 10-40 Tbps regimes.A five-year Total Cost of Ownership (TCO) analysis indicates 36-39% overall cost reduction, with 8-14 months break-even even in brownfield migrations.These findings provide robust evidence of OTN's economic and sustainability advantages and offer actionable decision support for operators, vendors, and policy makers pursuing cost-efficient, scalable transport modernization.