After you configure a dial plan to call a particular prefix in the PSTN, you notice that some outbound calls are taking longer than usual (15 seconds) before you hear a connecting tone. What is the…

Question

Options

• AThe outbound gateway must be configured with the new prefix.
• BThe endpoint is choosing the best codec to use.
• CThe new prefix is overlapping other route patterns.
• DWith some prefixes, this is normal behavior of the PSTN.

• A
  17% (10)
• B
  3% (2)
• C
  73% (44)
• D
  7% (4)

Explanation

When two or more route patterns overlap - meaning one pattern is a leading subset of another (e.g., '1800XXXXXXX' and '1800') - CUCM cannot immediately determine which pattern the user intends to match. It must wait for the interdigit timeout (governed by the T302 timer, default ~15 seconds) before concluding that no more digits are coming and committing to the best-matching pattern. The fix is to either terminate the shorter overlapping pattern with '#' (so users dial it explicitly), adjust the T302 timer, or redesign the patterns to eliminate the overlap. A misconfigured gateway, codec negotiation, or PSTN prefix behavior would not specifically cause a consistent 15-second pre-connection delay.

No community discussion yet for this question.