FRR

FRR is an acronym with several meanings across different fields, most commonly in networking and biometrics.

In networking, FRR can refer to Free Range Routing, an open-source routing software suite for Unix-like systems. FRR provides implementations of major routing protocols such as BGP, OSPF (including OSPFv3), IS-IS, RIP and RIPng, along with related protocols like PIM and BFD. It began as a fork of the Quagga project and is maintained by an active community of contributors and organizations. FRR runs on Linux and other platforms and uses a modular architecture of daemons that can be managed through a unified command-line interface (vtysh). It is widely used in data centers, service providers, and large-scale networks to enable flexible and scalable routing.

Fast ReRoute is another networking-related meaning of FRR. It denotes techniques and mechanisms designed to quickly reroute traffic in the event of a network failure, typically within milliseconds. Fast ReRoute relies on pre-computed backup paths and signaling methods (such as MPLS RSVP-TE or other IP-based mechanisms) to minimize traffic disruption after a link or node outage. It is used in high-availability networks, including service provider and large enterprise environments, where rapid recovery is critical.

In biometrics, FRR stands for False Rejection Rate, a performance metric indicating the proportion of genuine users who are incorrectly rejected by a biometric verification system. FRR is often discussed alongside FAR (False Acceptance Rate); system designers adjust thresholds to balance FRR and FAR to achieve desired accuracy and usability.

Context is essential to determine which meaning of FRR is intended, as the acronym spans distinct domains with related but separate concepts.