VoIP glossary · Least Cost Routing
What is LCR?
LCR (Least Cost Routing) is the practice of automatically sending each call over the cheapest available route for its destination, usually with quality rules so cost never overrides a working call.
LCR explained
An LCR engine looks up the dialled prefix, finds every carrier that can terminate it, and sorts them by rate. Good LCR does not stop at price: it also considers ASR, ACD, CLI requirements and capacity, and fails over to the next route if the first rejects the call.
Pure cost-first routing can backfire. A route that is a tenth of a cent cheaper but drops caller ID or has short calls can cost more in lost answers. Most operators keep a "quality" route for important traffic and let LCR pick among the rest.
Example
For prefix 4477 (UK mobile), MagnusBilling has three carriers ranked by rate. The cheapest returns 503, so the call is retried on the second within a fraction of a second.
Put it into practice
Prepaid SIP trunks and wholesale routes from $200. Ask sales for rates or the NOC for a technical answer.