{"id":13977,"date":"2026-05-27T08:15:08","date_gmt":"2026-05-27T08:15:08","guid":{"rendered":"https:\/\/www.siperb.com\/kb\/mobile-push-notifications\/"},"modified":"2026-05-27T08:15:08","modified_gmt":"2026-05-27T08:15:08","slug":"mobile-push-notifications","status":"publish","type":"post","link":"https:\/\/www.siperb.com\/kb\/mobile-push-notifications\/","title":{"rendered":"Siperb Mobile \u2014 Push Notifications for Any PBX"},"content":{"rendered":"\n

Getting missed calls on a mobile SIP softphone has been an unsolved problem for years. Either the app runs continuously in the background \u2014 draining the battery and eventually being killed by the operating system \u2014 or it goes silent and calls are missed entirely. Siperb’s mobile app now solves this properly: full push notification support for incoming calls on iOS and Android, working with any SIP PBX including Asterisk and FreePBX. And it’s free.<\/p>\n\n\n\n

Why SIP on mobile has always been a problem<\/h2>\n\n\n\n

SIP is a stateful protocol \u2014 receiving an incoming call requires your device to be actively registered with the PBX at the moment the call arrives. On a desktop, that’s trivial. On mobile, it isn’t.<\/p>\n\n\n\n

iOS and Android are both designed to suspend and terminate background processes to conserve battery. A SIP softphone running in the background will lose its registration within minutes \u2014 and when a call arrives, there’s nobody home. The workarounds people have tried \u2014 keeping the app permanently in the foreground, using persistent background services, shortening the SIP registration interval \u2014 all make things worse: more battery drain, more unreliability, more missed calls.<\/p>\n\n\n\n

The correct solution is push notifications. It’s the same mechanism that makes your phone ring when someone calls your mobile number. The operating system manages the wake-up entirely; the app doesn’t need to stay alive. Until now, this has required deep integration between the PBX vendor and Apple or Google \u2014 something that put it out of reach for anyone running Asterisk or an open-source PBX. Siperb changes that.<\/p>\n\n\n\n

How Siperb delivers push notifications for any PBX<\/h2>\n\n\n\n

When you register your PBX extension through Siperb, your mobile device registers with Siperb’s SIP proxy rather than directly with your PBX. The proxy maintains a persistent registration on your behalf \u2014 it stays alive so your app doesn’t have to.<\/p>\n\n\n\n

When an incoming call arrives, the sequence is:<\/p>\n\n\n\n

    \n
  1. Your PBX sends the SIP INVITE to Siperb’s proxy.<\/li>\n\n\n\n
  2. Siperb’s proxy sends a push notification via Apple APNs (iOS) or Google FCM (Android).<\/li>\n\n\n\n
  3. The operating system delivers the notification and wakes the Siperb app \u2014 even from a locked screen.<\/li>\n\n\n\n
  4. The app re-registers and the call connects.<\/li>\n<\/ol>\n\n\n\n

    The push notification is just the wake-up signal \u2014 no call audio travels through Apple or Google’s servers. Audio flows directly between your device and your PBX (via Siperb’s transcoding layer if your PBX uses plain RTP rather than WebRTC).<\/p>\n\n\n\n

    Free on all plans:<\/strong> Push notifications are included on Siperb’s free Personal plan. No paid subscription is required.<\/p>\n\n\n\n

    What you need<\/h2>\n\n\n\n