Which of the following commands is used to match both inbound and outbound dial peers?

destination-pattern

A. port

B. session target
C. incoming called-number
D. answer-address

Explanation:

Thedestination-pattern command is used to match both inbound and outbound dial peers; a dial peer defines a logical route to a telephony endpoint. The string variable that is used with the destination-pattern command must match the source Automatic Number Identification (ANI) for inbound dial peer matching and must match the destination Dialed Number Identification Service (DNIS) for outbound dial peer matching.

A voice gateway router will perform the following evaluations when it must send an outbound call:

1. The router will attempt to match the destination DNIS to a destination-pattern string command on a digit-by-digit basis, comparing the digit string to the destination-pattern as the user dials the digits.
2. If the dial peer is a plain old telephone service (POTS) dial peer, the router will forward the call to the port indicated by the corresponding port-port command.
3. If the dial peer is a Voice over IP (VoIP) dial peer, the router will forward the call to the IP address indicated by the corresponding session target ipv4: ip-address command.
4. If no match is found, the call will be dropped.

The dial peer evaluation process will occur for every call leg along the path from the source endpoint to the destination endpoint. A call leg is a logical inbound or outbound connection for a voice gateway. The originating voice gateway and the terminating voice gateway between two telephony endpoints have one call leg in the inbound direction and one call leg in the outbound direction. Therefore, there will beexactly two call legs for each voice gateway.

The port command is not used to match outbound dial peers; it is used by a voice router to match inbound POTS dial peers and to determine where to route outgoing POTS dial peers. The session target command isnot used to match outbound dial peers; it is used by a voice router to determine where to route an outgoing VoIP dial peer.

The incoming called-number command and the answer-address command are not used to match outbound dial peers? they are used to matchinbound dial peers. A voice router will perform the following evaluations when it receives an inbound call:

1. The router will attempt to match the destination DNIS to an incoming called-number DNIS command.
2. The router will attempt to match the sourceANI to an answer-address ANI command.
3. The router will attempt to match the source ANI to a destination-pattern string command.
4. The router will attempt to match the incoming call’s voice port to a port-port command.
5. If no match is found, the router will use the default dial peer.

Once a dial peer match is found, the router will immediately route the call without proceeding to the next step. If multiple matches are found for a step, the router will select the longest explicit match. The default dial peer will only be used if no match is found. You cannot configure any of the settings for the default dial peer.

Reference:
Cisco: Understanding Inbound and Outbound Dial Peers Matching on IOS Platforms
Cisco: Understanding Dial Peers and Call Legs on Cisco IOS Platforms: Relationship Between Dial Peers and Call Legs