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Configure Call Limits

Call Limit lets you cap concurrent outbound calls per destination prefix or trunk — useful to enforce a per-trunk channel cap separately from the trunk's own Maximum Channels, or to limit calls to expensive destinations (international prefixes).

Before You Start

  • You know what to limit: a destination dial pattern (e.g. 011. for international), an extension, or a route.
  • You know the cap.

Steps

  1. Go to Trunk Attributes → Outbound Call Limit.
  2. Click + Add Outbound Call Limit.
  3. Fill in:
    • Description — e.g. International Cap 2.
    • Pattern — dial pattern to match, e.g. 011. (matches all international), or 1900NXXXXXX (matches 900 numbers). Same pattern syntax as outbound routes.
    • Limit — max concurrent calls matching the pattern.
  4. Click Submit.
  5. Click Apply Config.

Verify

asterisk -rx "core show calls"
asterisk -rx "group show channels"

Place enough simultaneous calls matching the pattern. Once the cap is hit, additional matching calls should fail with "all circuits busy" or congestion.

Common Issues

  • Limit doesn't trigger. Pattern doesn't match the dialed number — review the dialplan trace to confirm what's being dialed.
  • Limit is global, not per-route. Outbound Call Limit is global. To cap per-route or per-extension, use the trunk's Maximum Channels OR Class of Service routing restrictions.
  • Counts include held/queued calls. Yes — call counters include all states until hangup.