Cisco Voice Guru

Dial-Peer Requirements

If Voice-Network (VoIP, VoFR, VoATM) and POTS dial-peers are not valid and in the "operational status", they are not considered for the Cisco IOS router/gateway inbound and outbound dial-peer matching process. In order to be considered valid/operational, dial-peers must meet one of these criteria:

• Destination-pattern and a voice-port or session target is configured.
• Incoming called-number is configured.
• Answer-address is configured.

SIP-based Dial-Peer to CUCM

dial-peer voice 50 voip
destination-pattern 5…
session target ipv4:10.10.210.11
preference 10
voice-class codec 1
voice-class sip 1
no vad
dtmt-relay rtp-nte
translation-profile outgoing E164-ANI

POTs Dial-Peer to T1 PRI on Serial 0/0/0:23

dial-peer voice 60 pots
destination-pattern 9[2-9]..[2-9]……
port 0/0/0:23
no vad
preference 10
dtmf-relay h245-alphanumeric
translation-profile outgoing E164-ANI
prefix 0

Validate Dial-Peers

In order to check the validity of the dial peer configuration, use the Cisco IOS command show dial-peer voice summary.  You can also perform debugging while sending calls out the gateway using debug voice dialpeer.

Below are the following destination-pattern operators that can be used in IOS dial-peers for voice:

Standard Operators

• Asterisk (*) and pound sign (#)—Keys that appear on standard touchtone dial pads.
• Brackets ([ ])—Range of digits. Digits (0 to 9) are enclosed in brackets. Similar to a regular expression rule.
• Parentheses (( ))—Define specific pattern. Same as the regular expression rule—for example, 408(555). Use parentheses in conjunction with symbols ? or %.
• Period (.)—Match to any entered digit (used as a wildcard).
• Comma (,)—Pause between digits.

“Repeating” Operators

• Percent sign (%)—The previous digit or pattern zero or multiple times, similar to wildcard usage in the regular expression.
• Question mark (?)—The previous digit occurred zero or one time.

Other Operators

• Circumflex (^)—Match to the beginning of the string.
• Dollar sign ($)—Match to the null string at the end of the input string.
• Backslash (\)—Is followed by a single character matching that character or used with a single  character having no other significance (matching that character).
• T—Control character indicating that the destination-pattern value is a variable-length dial string.

Overlap receiving allows the matching of dial peers as the digits are being entered.  I’m not aware of the benefits of ISDN overlap receiving, but it does exist and we need to be prepared for it on the voice lab.  Without overlap receiving, digits presented to available dial peers are sent en bloc, meaning that 5123 is analyzed as “5123″ and not “5″ … “1″ … “2″ … “3″

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