When there are multiple partitions and calling search spaces, it is possible that the route plan for the enterprise becomes complex and difficult to resolve if any issues arise at a later time.
In many cases, most of the Directory Number (DN) reachability issues are associated with duplicate DNs. The best way to resolve these issues is to generate a route plan report and review it carefully.
The route plan report also allows you to save report data into a .csv file that you can import into other applications. The .csv file contains more detailed information than the web pages, including DNs for phones, route patterns and translation patterns.
To learn how to generate these reports and how to interpret them, refer to these documents: