In today`s Voice over IP (VoIP) environment the final measure of network performance is provided by its users. A convergence of the network after the node failure in a traditional routing environment is simply too slow for voice users. Several attempts, mainly proprietary, have been introduced so far to speed up the network convergence. The new Bidirectional Forwarding Detection (BFD) protocol is standard based and as such interoperable between major router vendors.
In this IP Corner article, Ivan Pepelnjak, the Chief Technology Officer (CTO) at NIL Data Communications, describes how BFD is used in detecting two-way communication with the next-hop router to provide sub-second network convergence.