What is the function of a dial-peer?

• A. It stores user authentication data.
• B. It defines call routing rules on IOS voice gateways.
• C. It converts video codecs between endpoints.
• D. It manages media resource pools.

Answer: (B)

Dial-peers define how calls are routed on Cisco IOS voice gateways. They create the rules that map a dialed number (using destination-pattern) to a next hop or destination (session-target or port), effectively deciding where the call should go and how the media path is carried. In practice, you configure inbound dial-peers to handle calls entering the gateway and outbound dial-peers to specify how to reach the next endpoint, such as a SIP trunk, another gateway, or a PSTN line. Dial-peers can also specify media-related details like the codec to use, DTMF handling, and related options, but their primary role is routing the call through the network. The other options describe functions outside dial-peers: storing authentication data is handled by user databases/AAA, codec conversion is handled by codecs or transcoding resources, and managing media resource pools is a separate function related to media resources rather than the routing rules themselves.