Chapter 2: Webex Calling Design -- 2.4 Dial Plan Design¶
2.4 Dial Plan Design¶
Inherited from Phase 1
The enterprise numbering plan (4-digit extensions, site codes, inter-site ESN dialling, E.164 normalisation) was established in the CUCM→Webex Calling project and is unchanged here. The extension ranges below are a reference. Authoritative design: CUCM project Ch. 2.4 Dial Plan Design.
Contact centre agents use the same extension range as their site (e.g., Mumbai CC agents: 1000–1174 within site code 81). WxCC does not use a separate extension numbering scheme.
2.4.1 Extension Numbering¶
+-----------------------------------------------------------------------------+
| ABHAVTECH EXTENSION NUMBERING PLAN |
+-----------------------------------------------------------------------------+
| |
| EXTENSION FORMAT: 4 Digits |
| ========================== |
| |
| +--------------------------------------------------------------------+ |
| | Site Code | Location | Extension Range | Users Capacity | |
| +------------+-----------------+-----------------+-------------------+ |
| | 81 | Mumbai HQ | 1000-2199 | 1,200 extensions | |
| | 82 | Chennai | 2200-2649 | 450 extensions | |
| | 83 | Bangalore | 2650-2829 | 180 extensions | |
| | 84 | Delhi | 2830-2979 | 150 extensions | |
| | 85 | Noida | 2980-3099 | 120 extensions | |
| | 86 | Pune | 3100-3199 | 100 extensions | |
| | 87 | Hyderabad | 3200-3399 | 200 extensions | |
| | 91 | London | 4000-4519 | 520 extensions | |
| | 92 | Frankfurt | 4520-4799 | 280 extensions | |
| | 93 | New Jersey | 5000-5479 | 480 extensions | |
| | 94 | Dallas | 5480-5749 | 270 extensions | |
| +------------+-----------------+-----------------+-------------------+ |
| |
| RESERVED RANGES: |
| ================ |
| 0XXX - Reserved for future |
| 6XXX - Reserved for system features |
| 7XXX - Auto Attendants and Call Park |
| 8XXX - Hunt Groups and Queues |
| 9XXX - Reserved (avoid OAC conflict) |
| |
| CONFLICT AVOIDANCE: |
| ================== |
| * First digit of extensions (1-5) ≠ Steering digit (8) ≠ OAC (9) |
| * No extension starts with 8 or 9 |
| |
+-----------------------------------------------------------------------------+
2.4.2 ESN (Enterprise Significant Number) Format¶
+-----------------------------------------------------------------------------+
| ESN DIAL PLAN - INTER-SITE DIALING |
+-----------------------------------------------------------------------------+
| |
| ESN FORMAT: 8 - XX - XXXX |
| | | | |
| | | +-- Extension (4 digits) |
| | +-------- Site Code (2 digits) |
| +------------ Steering Digit |
| |
| EXAMPLES: |
| ========= |
| Mumbai user calling Chennai extension 2100: |
| Dial: 8-82-2100 -> Routes to Chennai ext 2100 |
| |
| London user calling Mumbai extension 1500: |
| Dial: 8-81-1500 -> Routes to Mumbai ext 1500 |
| |
| Dallas user calling Frankfurt extension 4600: |
| Dial: 8-92-4600 -> Routes to Frankfurt ext 4600 |
| |
| ESN ROUTING TABLE: |
| ================== |
| +----------------+----------------+---------------------------------= |
| | ESN Prefix | Location | Route | |
| +----------------+----------------+---------------------------------+ |
| | 881XXXX | Mumbai HQ | ABV-Mumbai-HQ | |
| | 882XXXX | Chennai | ABV-Chennai | |
| | 883XXXX | Bangalore | ABV-Bangalore | |
| | 884XXXX | Delhi | ABV-Delhi | |
| | 885XXXX | Noida | ABV-Noida | |
| | 886XXXX | Pune | ABV-Pune | |
| | 887XXXX | Hyderabad | ABV-Hyderabad | |
| | 891XXXX | London | ABV-London | |
| | 892XXXX | Frankfurt | ABV-Frankfurt | |
| | 893XXXX | New Jersey | ABV-NewJersey | |
| | 894XXXX | Dallas | ABV-Dallas | |
| +----------------+----------------+---------------------------------+ |
| |
| CONFIGURATION: |
| Control Hub -> Calling -> Dial Plan -> Location Routing Prefix |
| |
+-----------------------------------------------------------------------------+
2.4.3 PSTN Routing by Region¶
India PSTN Dial Plan:
| Pattern | Description | Route |
|---|---|---|
| 9[2-9]XXXXXXXXX | India local/STD | Zone LGW |
| 9011[1-9]X. | International | Zone LGW |
| 100 | Police | Emergency |
| 101 | Fire | Emergency |
| 102 | Ambulance | Emergency |
| 1800XXXXXXX | Toll-Free | Zone LGW |
UK PSTN Dial Plan:
| Pattern | Description | Route |
|---|---|---|
| 901[0-9]XXXXXXXX | UK geographic | CCPP |
| 90800XXXXXXX | UK toll-free | CCPP |
| 9+[1-9]X. | International | CCPP |
| 999 | Emergency | Emergency |
| 112 | EU Emergency | Emergency |
Germany PSTN Dial Plan:
| Pattern | Description | Route |
|---|---|---|
| 0[1-9]X. | German national | CCPP |
| 00[1-9]X. | International | CCPP |
| 112 | EU Emergency | Emergency |
US PSTN Dial Plan:
| Pattern | Description | Route |
|---|---|---|
| 91[2-9]XXXXXXXXX | US domestic | CCPP |
| 9011[1-9]X. | International | CCPP |
| 911 | Emergency | E911 |
| 91800XXXXXXX | Toll-Free | CCPP |
2.4.4 Emergency Calling Configuration¶
+-----------------------------------------------------------------------------+
| EMERGENCY CALLING CONFIGURATION BY REGION |
+-----------------------------------------------------------------------------+
| |
| INDIA: |
| ====== |
| Emergency Numbers: 100 (Police), 101 (Fire), 102 (Ambulance), 112 |
| Callback Number: Per-location main number |
| Address Format: Manual entry (no automated E-CNAM in India) |
| Routing: Via Local Gateway to local PSTN |
| |
| UK: |
| === |
| Emergency Numbers: 999, 112 |
| Callback Number: User's DID |
| Address Format: BT Openreach validated |
| Routing: Via CCPP |
| |
| GERMANY (EU): |
| ============= |
| Emergency Number: 112 (EU standard) |
| Callback Number: User's DID |
| Address Format: German address format (Straße, PLZ, Stadt) |
| Routing: Via CCPP |
| |
| USA: |
| ==== |
| Emergency Number: 911 |
| Service Type: E911 (Enhanced 911) |
| Callback Number: User's DID |
| ELIN: Assigned per location |
| Address: Validated dispatchable address per user |
| Routing: Via CCPP with E911 lookup |
| |
| REMOTE/WFH USERS: |
| ================= |
| * Users prompted to update emergency address in Webex App |
| * Nomadic E911: Address follows user, not device |
| * India WFH: 112 routes to Webex-provided emergency service |
| * US WFH: E911 with user-declared address |
| |
+-----------------------------------------------------------------------------+