Configuring Dial Peers for Use
Configuring dial peers is essential when designing and implementing Voice over
IP on your network. Dial peers identify the calling source and the destination
points so as to define what attributes are assigned to each call. In the telecommunications
world, calls routed over the PSTN are assigned to a dedicated 64KB
circuit from start to end. In the data world, a voice call must traverse segments
within the network referred to as call legs.This isn’t to say that these don’t exist
in the telecomm world, they are just more noticeable within packet-based
networks.
A call leg is the connection that occurs between the calling device and the
router, router-to-router along the path, and from the router to the end device.A
dial peer is linked with each of these segments, and it’s here where the defined
attributes are added to the call.Things like the CODEC,VAD, and QoS are utilized
depending on whether you have defined them for that link.
There are several types of dial peers, but those we’ll focus on here are VoIP
and POTS.VoIP dial peers are associated with the IP address of the destinations
router so it can connect and terminate a call from an IP-based telephony device.
POTS dial peers are basically the telephone system as we know it.These dial
peers map dialed digit strings to specific voice ports that are located on the
router.These voice ports are usually associated with the PSTN and the PBX.