# UCM 3.0
> A mobile-first enterprise communications model with stronger native network integration

UCM 3.0 emphasizes native dialer and SIM/eSIM integration while coexisting with OTT UC apps.

## What is UCM 3.0?
UCM 3.0 is a modern enterprise communication model that integrates calling more deeply with mobile-native capabilities such as SIM or eSIM identity and native dialer behavior.

## UCM 3.0 and OTT coexistence
UCM 3.0 improves transport reliability and user familiarity, while OTT unified communications apps continue to provide extensibility, workflow integration, and rapid feature innovation.

## Related Terms
- [Unified Communications](/voip-glossary/unified-communications/)
- [OTT](/voip-glossary/ott/)
- [eSIM](/voip-glossary/esim/)