T2 · T2-R03
Transformations
Learn it in 5 minutes
- Called, calling, and redirecting numbers are different fields.
- A mask can fix or break caller ID.
- Translation patterns change digits and can change the CSS.
- External phone number masks are a presentation tool.
- Write the digits before and after each step.
Visual
What is going on
Most 'wrong caller ID' tickets are a mask on the route pattern, the route list, or the trunk, applied in an order the engineer did not draw. Capture the outgoing INVITE and compare it with the directory number.
Worked example
Users dial 9 and a national number. The pattern strips the 9 and prefixes the carrier's expected digits. The calling number is masked to the site's main number. If the mask is the directory number instead, the carrier may reject the call.
Quiz
1. The calling number and the called number are the same field.
False.
Ecosystem
Sister pieces sit on the ecosystem page: the glossary, the mind map, the integration map, and the sibling labs.
- Translation pattern — A pattern that transforms digits and can continue routing.
- Mask — A digit rewrite applied to a number field.
Config. On the ladder, copy the From and the Request-URI after the trunk.
Troubleshooting. If inbound calls show the wrong name, look at inbound transformations and the directory lookup, not only outbound masks.
Bridge. Local gateway digit manipulation on IOS and CUCM masks can both run. Decide which box owns the plan.
Mind map, sister technologies, and future hooks live on the ecosystem page.
Sources
Product screens move. Confirm the guide for your release before you change a live system.
Sources and go deeper
Opened 2026-10. A row marked confirm has no link, because that page was not verified.
- Cisco. Cisco Unified Communications Manager product support last checked 2026-10
- Cisco. System Configuration Guide for CUCM, Release 15 last checked 2026-10
- Cisco. Cisco Collaboration Preferred Architectures last checked 2026-10
- Cisco. Preferred Architecture for Cisco Collaboration 15, design overview (PDF) last checked 2026-10
- Protocol and ports. CUCM 15 TCP and UDP port usage last checked 2026-10
- Protocol and ports. IANA SIP parameters last checked 2026-10
- Community. Cisco Community, Collaboration knowledge base last checked 2026-10
- Wikipedia. Voice over IP (Wikipedia) last checked 2026-10
- Wikipedia. CUCM (Wikipedia disambiguation) last checked 2026-10
- Cisco. Collaboration 12 SRND book. confirm. The historical Collaboration 12 SRND path opened as a product listing, not the design book. Use the Preferred Architecture index, which was opened. last checked 2026-10
- Wikipedia. English Wikipedia article for Cisco Unified Communications Manager. confirm. That title returned HTTP 404. The CUCM disambiguation page is the Wikipedia page that opened. last checked 2026-10