A customer routes PSTN calls to its ITSP through a SIP trunk on Cisco UCM that forwards and receives calls to and from ITSP. ITSP is set to send an E.164 number when the customer's extension is four d

Question

Options

• AConfigure a voice translation profile to map the E.164 number to four digits and assign it to the incoming dial-peer on Cisco Unified Border Element.
• BSet the Significant Digits to 8 on the SIP trunk.
• CSet the Significant Digits to 4 on the SIP trunk.
• DConfigure a voice translation rule to map the E.164 number to four digits and assign it to the incoming dial-peer on Cisco Unified Border Element.

• A
  16% (6)
• B
  5% (2)
• C
  71% (27)
• D
  8% (3)

Explanation

The 'Significant Digits' setting on a Cisco UCM SIP trunk controls how many digits, counted from the right (least significant) end of the incoming called-party number, are passed into UCM for digit analysis and routing. When the ITSP sends a full E.164 number (e.g., +19195551234) but internal extensions are four digits (e.g., 1234), setting Significant Digits to 4 causes UCM to strip all leading digits and present only the last four to the dial plan. This matches the four-digit DNs and routes the call correctly. Setting it to 8 would pass eight digits, which would not match a four-digit DN pattern.

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