Cisco Systems 3600 manual Configure Dial Peers, Inbound versus Outbound Dial Peers

Configure Dial Peers

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 6 and Figure 7. A call leg is a discrete segment of a call connection that lies between two points in the connection. All the call legs for a particular connection have the same connection ID.

There are two different kinds of dial peers:

•POTS—Dial peer describing the characteristics of a traditional telephony network connection. POTS peers point to a particular voice port on a voice network device.

•VoIP—Dial peer describing the characteristics of a packet network connection; in the case of Voice over IP, this is an IP network. VoIP peers point to specific VoIP devices.

Four call legs make comprise and end-to-end call—two from the perspective of the source router as shown in Figure 6, and two from the perspective of the destination router as shown in Figure 7. A dial peer is associated with each one of these call legs. 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.

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’s perspective. An inbound call leg originates outside the router. An outbound call leg originates from the router.

For inbound call legs, a dial peer might be associated to the calling number or the port designation. 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.

VC-26Voice, Video, and Home Applications Configuration Guide