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VOBIZ VoIP Call

Native Kotlin SIP/WebRTC dialer for Vobiz PSTN

Android 12+ Jetpack Compose softphone for inbound and outbound PSTN via Vobiz: SIP over secure WebSocket, WebRTC audio, recents/keypad UI, and a TypeScript Answer URL / FCM backend.

Kotlin
GitHub

Abstract

Vobiz VoIP Dialer is a native Kotlin Android 12+ Jetpack Compose softphone for inbound and outbound PSTN through Vobiz. Signaling is SIP over a secure WebSocket; media is WebRTC.

Problem

Embedding PSTN calling needs a real dialer — recents, keypad, number normalization, and app-to-app intents — not a vendor sample.

Solution

A native-phone-style dialer with SIM/default-country number normalization, its own call history, and documented intents so other apps can place a call.

Architecture

  • Android 12+ Jetpack Compose softphone.
  • TypeScript Answer URL, call-state, and FCM service.
  • SIP over secure WebSocket; WebRTC audio.

Capabilities

  • Inbound and outbound PSTN via Vobiz.
  • Recents, keypad, device-contact search, and Settings.
  • ACTION_DIAL and explicit CALL intents for other apps.

Audience

Teams embedding Vobiz PSTN in Android products, and anyone needing a native counterpart to MAUI VoipCore.

Outcomes

  • A documented calling stack with UI, backend, and webhook contracts.
  • App-to-app dialing without relying on the system call log.

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