A dial peer, also known as an addressable call endpoint, is a device that can originate or
receive a call in a telephone network. In voice over IP (VoIP), addressable call endpoints can be
categorized as either voice-network dial peers or POTS (plain old telephone service) dial peers.
Voice-network dial peers include VoIP-capable computers, routers, and gateways within a
network. POTS dial peers include traditional phone sets, cell phones, and fax machines.
The term dial peer is sometimes used in reference to a program that matches a specific
dialed sequence of digits to an addressable call endpoint. According to this definition, there is
one dial peer for each call leg (connection between two addressable call endpoints).
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. 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.