The dial plan and call routing are among the most complex and critical components of any Cisco Unified Communications system and deployment. Whether implementing a single-site or multisite solution, a deep understanding of these components — and how to configure them in Cisco Unified Communications Manager (CUCM) — is essential for any voice engineer. In essence, the dial plan acts as the decision-maker, instructing the call processing agent on how to route calls effectively. Goals and Methods: When discussing dial plans and call routing, many components come into play: route patterns, route lists, route groups, trunks, gateways, as well as translation patterns and transformation patterns used for digit manipulation of called and calling parties. This book is written to demystify the dial plan and call routing — especially the components used to implement them — using atypical, real-world scenarios. It will help answer questions such as: • How do translation patterns work? • How do transformation patterns work? • What is the difference between them? • Where and how should they be implemented? At what level should digit manipulations occur — route pattern, route group, phone (external phone number mask), or gateway? One of the most critical parts of the dial plan — Globalized Call Routing or Unified Dial Plan using the +164 format — is covered in detail. You’ll understand why a unified dial plan is necessary, and how it simplifies features such as: • Device Mobility • AAR (Automated Alternate Routing) • Emergency Numbers • Class of Service • TEHO (Tail-End Hop Off) Webex Calling Integration Additionally, this book covers Webex Calling and cloud-based call control, aligning with Cisco’s modern collaboration solutions. You’ll gain insights into Webex Calling components, features, and call routing logic with PSTN or on-premise CUCM using: • Local Gateway • Trunks • Dial Plan • Route Groups • Dial peers on the Local Gateway Practical Approach The dial plan and call routing topics are presented with practical, atypical explanations and lab scenarios to help you truly grasp what’s happening under the hood. You'll walk away with a concrete sense of: • “This is how a call is routed,” and • “This is how a specific feature works.”