Wholesale glossary
Least Cost Routing is the discipline of sending each call (or message) down the cheapest available path that still meets quality requirements. Mature LCR is not simply cheapest-first: it scores routes on cost and quality together (ASR, ACD, PDD), excludes what fails baseline, and steers traffic in near real time as routes degrade or prices change.
Why it matters
Naive LCR is how carriers buy themselves a fraud problem: the cheapest route on a corridor is often cheap because someone is refiling, bypassing or grey-routing the traffic. Quality-guarded LCR exists precisely because cost-only optimization is a margin today, a leak tomorrow.
What practitioners watch
The modern layer is prediction: steering on expected answer rate and duration per route rather than trailing averages, with automatic failover. That is where routing stops being a table and starts being a system.
Related: Routing Optimization · Routing Quality Observatory · ASR