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Which of the following dial peer commands will not match dial strings 3331, 3332, and 3333?
- destination-pattern .T
- destination-pattern 33T
- destination-pattern ….
- destination-pattern 333.
- destination-pattern 333(123)
- destination-pattern 3+[123]
- destination-pattern 333[^49]
Explanation:
The dial peer command destination-pattern 333(123) will not match dial strings 3331, 3332, and 3333. The destination-pattern command is used to match both inbound and outbound dial peers; a dial peer defines a logical route to a telephony endpoint. The sequence of dialed digits that will be matched for a dial peer can contain the digits 0 through 9, the asterisk (*), and the pound sign (#). In addition, you can use the following symbols to refine the dialing pattern or to match multiple dial strings for a single dial peer:
Parentheses are used to indicate a specific sequence of characters. Therefore, the dial peer command destination-pattern 333(123) will match only the dial string 333123. Parentheses are often used with the %, +, and ? characters to indicate a repeating pattern. For example, the destination-pattern 333(123)% command matches 333, 333123, 333123123, 333123123123, and so on.
The following dial peer commands will match dial strings 3331, 3332, and 3333:
-destination-pattern .T
-destination-pattern 33T
-destination-pattern ….
-destination-pattern 333.
-destination-pattern 3+[123]
-destination-pattern 333[^49]
The dial peer command destination-pattern .T is used to indicate any string of up to 32 digits. The T character is used at the end of a string to instruct the router to wait for the complete dial string to be entered before matching a call to a dial peer. Cisco recommends that you use the destination-pattern .T command rather than the destination-pattern T command because the destination-pattern .T command requires that the caller dial a digit. By default, a dial peer with the destination-pattern T command will be matched if an outbound caller takes the phone off-hook for 10 seconds.
The dial peer command destination-pattern 33T matches any dial string of up to 32 digits that begins with 33. Not only will the dial peer command destination-pattern 33T match 3331, 3332, and 3333, it will also match 334567 and 3331234, among others. However, if a dial string matches multiple dial peers, the longest explicit match is chosen. For example, if one dial peer contains the destination-pattern 333T command and another dial peer contains the destination-pattern 3334T command, a call from a caller dialing 3334000 would match the second dial peer.
The dial peer command destination-pattern …. matches any four-digit dial string. The period is used as a wildcard character that matches any digit. Therefore, the destination-pattern …. command matches dial strings 3331, 3332, 3333, 0000, 1257, and 6538, among many others.
The dial peer command destination-pattern 333. matches any four-digit dial string that begins with 333. Not only will the destination-pattern 333. command match 3331, 3332, and 3333, it will also match 3330, 3334, 3335, 3336, and so on.
The dial peer command destination-pattern 3+[123] matches any dial string that contains one or more 3s and ends with a 1, 2, or 3. The plus sign indicates that the preceding digit can occur one or more times. The square brackets are used to indicate that the pattern should match any of the bracketed digits for that digit position. Therefore, not only does the destination-pattern 3+[123] command match the dial strings 3331, 3332, and 3333, it also matches the dial strings 31, 32, 33, 331, 332, 333, 333331, 3333332, and 33333333333, among many others.
The dial peer command destination-pattern 333[^49] matches any dial string that starts with 333 and ends with a digit that is not 4 through 9. The caret symbol (^) can be used within square brackets to indicate characters that should not match. The dash can be used between two digits within brackets to indicate a range of characters. Therefore, the destination-pattern 333[^49] command matches the dial strings 3330, 3331, 3332, 3333, and 333*, but the command does not match the dial strings 3334, 3335, 3336, 3337, 3338, and 3339.
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