dial peer hunting

Dial peer hunting is a feature of voice over IP (VoIP) systems in which the device at the originating router attempts to find an alternative addressable call endpoint if it cannot establish a connection to the intended endpoint. In Internet telephony, an addressable call endpoint, also known as a dial peer, is a device (such as a standard phone set, cell phone set, fax machine, VoIP-capable computer, or router) that can originate or receive a call.

For dial peer hunting to work, the originating router must be configured with a list (sequence) of dial peers, all of which can route a call to the same endpoint, but using different destination routers. If the originating router receives an invalid-number or user-busy code from the destination router, the originating router proceeds to the next dial peer in the sequence.