National Dialing, Site Codes, and 911 Routing
Northwind has CUCM 14 at HQ and a branch, each with a local CUBE. Extensions are 4 digits: HQ 1000-1999, branch 2000-2999. All sites use access code 9. The existing route pattern is 9.@ with discard pre-dot, pointing to a single route group containing both CUBEs. The carrier requires national calls as +1XXXXXXXXXX and international as +CCXXXXXXXX. Users report: 9 + 10-digit national calls fail with SIP 503 from the carrier; 9 + 011 + international fail with 404; 911 from the branch reaches the HQ PSAP, not the branch PSAP; and branch users cannot dial HQ extensions after a recent partition change. CUCM traces show the national call leaving CUCM as 4155551212, and CUBE sends it unchanged. The branch CUBE has a dial-peer to the carrier only; 911 is not specially routed. The customer wants 4-digit site dialing and correct 911 without a full renumber.
1. Diagnose the national and international call failures and propose the required route patterns and transformations.
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CUCM is sending 4155551212 to CUBE because route pattern 9.@ discards only the 9 and does not prefix +1. The carrier rejects that Request-URI with 503. International calls fail with 404 because 9.@ also matches 9011... and sends 011... without the required +. Replace the catch-all with explicit patterns: 9.1[2-9]XX[2-9]XXXXXX, discard pre-dot 9, prefix +1; 9.011[1-9]T, discard 9, prefix +. Block unintended 9.@ patterns. Add called-party transformations on CUBE as a second line of defense, but keep normalization in CUCM so traces show the intended E.164. Verify with DNA and debug ccsip messages that the INVITE Request-URI is +14155551212. Also check the carrier's accepted numbering plan and whether it wants +1 for national only or for all NANP calls.
2. How would you restore 4-digit inter-site dialing between HQ and the branch after the partition change?
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The branch cannot dial HQ because the partition/CSS change removed HQ's 1XXX pattern from the branch CSS, or because the SIP trunk route pattern points to the wrong route group. Restore a route pattern 1XXX in a partition included in the branch CSS, pointing to the HQ SIP trunk or route group. If using a global dial plan, translate 1XXX to +14155551XXX and let the +E.164 routing take over. Confirm that the branch CUBE does not reject 1XXX before it reaches CUCM; use debug voice dialpeer if needed. Avoid overlapping patterns such as 1XXX and 1[0-9]XX. Test both directions and check calling search space order.
3. What design changes are needed so branch 911 calls reach the correct PSAP and present the right location data?
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911 must not depend on the general 9.@ route. Create a dedicated 911 pattern with urgent priority in a partition always included in every CSS. Use a local route group per site so branch 911 uses the branch CUBE and a PSAP trunk, not the HQ CUBE. Configure CER with the branch ELIN and correct ALI data, and make sure the branch CUBE sends the ELIN, not the main number. Also handle 9911 if users dial 9 first. Test with the PSAP on a non-emergency test number, and confirm the ANI/ELIN presented. Do not rely on carrier default routing.