Voice Fraud & Compliance Wiki

    SIP & Network

    LRNLocation Routing Number

    The routing number that identifies the switch actually serving a telephone number after number portability, used to route ported calls correctly.

    When a subscriber ports their number, the dialed number no longer indicates the serving carrier. An LRN dip against the portability database returns the number that identifies the correct terminating switch.

    LRN data also reveals the true carrier and rate centre behind a number, which is useful context in fraud and access-stimulation analysis.

    Why it matters to carriers

    Routing on the dialed number instead of the LRN produces misrouted calls and mis-rated traffic, both of which distort fraud baselines.

    Handling lrn on your own switch

    SipShield scores live SIP traffic with patented AI so the controls behind this term run automatically — and leave the audit trail regulators expect.