Specifications

Configure Dial Peers
Voice over IP for the Cisco AS5300 27
After you have configured dial peers and assigned destination patterns to them, you can verify
number expansion information by using the show dialplan number command to learn how a
telephone number maps to a dial peer.
Configure Dial Peers
The key point to understanding how Voice over IP functions is to understand dial peers. Each dial
peer defines the characteristics associated with a call leg, as shown in Figure 5 and Figure 6. Dial
peers are used to apply attributes to call legs and to identify call origin and destination. Attributes
applied to a call leg include QoS, CODEC, VAD, and fax rate. A call leg is a discrete segment of a
call connection that lies between two points in the connection. All of the call legs for a particular
connection have the same connection ID.
An end-to-end call is comprised of four call legs, two from the perspective of the source router or
access server as shown in Figure 5, and two from the perspective of the destination router or access
server as shown in Figure 6. A dial peer is associated with each one of these call legs.
Figure 5 Dial Peer Call Legs from the Perspective of the Source Router or Access
Server
Figure 6 Dial Peer Call Legs from the Perspective of the Destination Router or Access
Server
There are two different kinds of dial peers as shown in both Figure 5 and Figure 6:
POTS—POTS dial peers describe the line characteristics usually associated with a traditional
telephony network; in VoIP for the Cisco AS5300, they describe the the specific line characteristics
between the telephony device and the Cisco AS5300. POTS dial peers point to a particular voice port
on a network device—in the case of VoIP for the Cisco AS5300, they point to a specific voice port
on the Cisco AS5300 through which voice traffic will travel to the rest of the voice network.
10353
IP cloud
Destination
Source
Call leg for POTS
dial peer 1
Source router
Call leg for VoIP
dial peer 2
10354
IP cloud
Destination router
Call leg for POTS
dial peer 4
Call leg for VoIP
dial peer 3
Destination
Source