Specifications

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Cisco 1751 Router Software Configuration Guide
OL-1070-01
Figure 3 Dial Peer Call Legs from the Perspective of the Source Router
Figure 4 Dial Peer Call Legs from the Perspective of the Destination Router
There are basically two different kinds of dial peers with each voice implementation:
• POTS—(also known as “plain old telephone service” or “basic telephone service”) dial peer
associates a physical voice port with a local telephone device, and the key commands you need to
configure are the port and destination-pattern commands. The destination-pattern command
defines the telephone number associated with the POTS dial peer. The port command associates
the POTS dial peer with a specific logical dial interface, normally the voice port connecting your
router to the local POTS network.
• Vo I P —dial peer associates a telephone number with an IP address, and the key commands you need
to configure are the destination-pattern and session target commands. The destination-pattern
command defines the telephone number associated with the VoIP dial peer. The session target
command specifies a destination IP address for the VoIP dial peer. In addition, you can use VoIP
dial peers to define characteristics such as IP precedence, additional QoS parameters (when RSVP
is configured), CODEC, and VAD.
Inbound versus Outbound Dial Peers
Dial peers are used for both inbound and outbound call legs. It is important to remember that these terms
are defined from the router perspective. An inbound call leg means that an incoming call comes to the
router. An outbound call leg means that an outgoing call is placed from the router.
For inbound call legs, a dial peer might be associated with the calling number or the voice-port number.
Outbound call legs always have a dial peer associated with them. The destination pattern is used to
identify the outbound dial peer. The call is associated with the outbound dial peer at setup time.
18944
IP cloud
Destination
Source
Call leg for POTS
dial peer 1
Call leg for VoIP
dial peer 2
24418
Destination
Source
IP cloud
Call leg for POTS
dial peer 4
Call leg for VoIP
dial peer 3