LRN (Location Routing Number)
Location Routing Number (LRN) is an identification for a telephone switch for the purpose of routing telephone calls through the PSTN (public switched telephone network) in the United States.
When telephone numbers port over from another carrier, Bandwidth assigns an LRN to the number to ensure routing is correct.
A LRN is part of how calls are routed, namely calls to ported or pooled numbers are routed based on the NPA-NXX of the number’s associated LRN. If a customer ports their number to another provider, the current telephone number can be retained and only the LRN needs to be changed.
Each carrier has at least one LRN per LATA. LRNs were created to provide local number portability by allowing numbers to route successfully when moved between carriers.