This object stores an alternate routing metric for the forward direction of an ATM PNNI route, specifically the cumulative Cell Delay Variation (CDV) measured in microseconds. It's used by PNNI routing nodes to calculate the best path for ATM connections based on quality-of-service requirements, helping determine if a route can meet delay variation constraints. Network operators would check this value when troubleshooting call setup failures, optimizing routes for real-time traffic, or analyzing path computation metrics for voice and video services.