Globalized Call Routing E.164 Standard

350-801 By islever Editorial Last updated Aug 20, 2026

Short answer

A Internal to External -

Question

All calls that involve external parties must be based on a format to simplify the International multisite dial plans when globalized call routing is used. Which standard must be followed to implement normalized call routing?

Internal to External - Correct Answer
External to Internal -
External (local number) to Internal
Internal to External (local number)

Key Takeaways

The exam tests knowledge of number normalization formats, specifically trapping candidates who confuse internal DN usage with external E.164 requirements for globalized routing.

This question addresses the requirements for simplifying international multisite dial plans using globalized call routing in Cisco Unified Communications Manager (CUCM). The community consensus confirms that adhering to the E.164 standard for both calling and called party numbers is essential for normalized call routing.

Common mistake: Candidates may select options involving 'local numbers' or 'external to internal' because they misunderstand that normalization requires converting all numbers to a global standard (E.164) before routing, rather than keeping them local or only transforming one direction.

Expert Analysis

Why the Answer Is Correct

Option A is correct because globalized call routing relies on the E.164 standard to ensure consistency across international sites. In this format, both the calling-party number and the called-party number are represented in E.164 format. This allows CUCM to perform digit manipulation and translation consistently regardless of the originating location, simplifying the dial plan.

Why the Other Options Are Wrong

Options B and C involve 'External' as the source or destination in ways that do not describe the normalization process itself. Option D suggests using local numbers for external calls, which contradicts the goal of globalized routing. Normalization strips local prefixes and translates numbers into a global format; it does not retain local formatting for egress without prior conversion.

Community Comment Notes

Comment [3] provides a clear breakdown: 'Calling-party number: E.164 Called-party number: E.164'. Comment [1] links to Cisco's official collaboration knowledge base, confirming that internal-to-external scenarios require E.164 adherence for globalized routing. Comment [2] correctly notes that DNs are for internal destinations and that localization is different from normalization.

Community Votes

100%

100% of anonymous learners picked answer A. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 4 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 4

c6176b5 👍 3 Answered A

I guess the question builder used this source, so A would be correct: https://community.cisco.com/t5/collaboration-knowledge-base/basics-of-globalized-call-routing/ta-p/3121674
G0y0 👍 1 Answered A

B. and C. are incorrect. DNs are used for internal destinations. Normalization is achieved by stripping or translating the called number to internally used DNs. D. Is partially correct. It is localized call egress, not normalization. Even in this case, it is the called number which must be localized. Localizing is issued using Translations and Transformation Patterns in the local Gateway or the local Trunk, but it is not performed in the side of the Globalized Call Routing environment. A. is correct. E.164 global format is used for all calling-party numbers, except calls from an internal number to another internal number. Reference: It is very well explained in the book "Implementing Cisco IP Telephony and Video, Part 2 (CIPTV2) Foundation Learning Guide" Chapter 3: Overview of PSTN and Intersite Connectivity Options. I recommend get these ebooks in non-official search engines. The ebooks are difficult to get in those official ones
b3532e4 👍 1

A. Internal to External - Calling-party number: E.164 Called-party number: E.164 This format ensures consistency across international multisite dial plans when globalized call routing is used, as both the calling and called party numbers adhere to the E.164 standard, which is crucial for simplifying international routing across different locations and systems
e971987 👍 1 Answered A

GLOBALIZED CALL ROUTING. A. Internal to External - Calling-party number: E.164 - Called-party number: E.164

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