Siperb Mobile Softphone

The Siperb mobile app puts your office phone extension on your iOS or Android device. It uses your existing PBX — Asterisk, FreePBX, FreeSWITCH, or any SIP system — and delivers calls to your mobile the same way a native dialler does: with a push notification that wakes your phone even when the app is closed. No PBX-side changes required.

Push notifications — calls arrive even when the app is closed

This is the headline feature. Keeping a SIP softphone alive on a mobile device has historically been a hard problem — iOS and Android both kill background processes to save battery, which means the app loses its SIP registration and incoming calls are missed.

Siperb solves this at the infrastructure level. When a call arrives for your extension, Siperb’s proxy sends a push notification directly to your device via Apple APNs (iOS) or Google FCM (Android). The operating system wakes the app, it re-registers, and your phone rings — whether the app was in the background, the screen was locked, or the device had just restarted.

Push notifications are included on the free Personal plan. See the full technical detail in Siperb Mobile — Push Notifications for Any PBX →

Works with any SIP PBX

Siperb’s proxy sits between your mobile device and your PBX, handling the translation and the push integration. Your PBX sees a standard SIP registration — there is nothing to configure on the PBX side beyond allowing external registration. If you can provision a SIP extension, Siperb can deliver it to a mobile device with push notifications.

This includes Asterisk and FreePBX, which between them power the majority of self-hosted PBX deployments worldwide. See Asterisk Softphone → for a step-by-step Asterisk setup guide.

iOS and Android

Both platforms are fully supported with platform-native push implementations:

  • iOS (18+) — uses Apple PushKit (VoIP push), giving calls the same OS priority as the native Phone app. Rings reliably through locked screens, Do Not Disturb exceptions, and battery saver mode.
  • Android (Android 8 / SDK26) — uses Firebase Cloud Messaging (FCM) with a high-priority flag, delivering consistent wake-up behaviour across manufacturers and Android versions.

Full softphone features on mobile

Push notifications get the call to your device. Once connected, the full Siperb feature set is available:

  • Audio and video calls
  • Attended and blind transfer
  • Three-way conference
  • DTMF (for IVR navigation, door entry, etc.)
  • Call history and CDR
  • Buddy list and presence
  • End-to-end encryption (TLS + DTLS-SRTP)

Getting started