sip2go client

SIP2GO is the Android client for the SIP2GO gateway — a self-hosted server you deploy on your own infrastructure.
⚠️ THIS APP DOES NOT WORK STANDALONE
SIP2GO is not a public VoIP service and not a classic SIP softphone. It does not provide phone numbers, SIP accounts, or cloud telephony by itself. You must install and operate the SIP2GO gateway server (and typically Asterisk or another PBX) before this app can make or receive calls.
If you do not have a SIP2GO server, this app will not function.
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HOW IT WORKS
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You host the server → you configure Asterisk → you register this phone as an extension.
Asterisk / PBX ←→ SIP2GO gateway (your server) ←→ this Android app
The gateway registers to your PBX as a normal SIP endpoint. The app connects to your gateway over encrypted WebSocket (TLS) and carries voice using the Opus codec. No SIP stack runs on the phone — your server does the heavy lifting.
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WHAT YOU NEED TO DEPLOY
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• SIP2GO gateway — open-source server component (Python), hosted by you
• Asterisk or compatible SIP/PBX on your LAN or datacenter
• Public HTTPS URL for the gateway (for WebSocket and push wake)
• To use Push mode: get access to the centralized Push Relay — a service for centralized delivery of FCM push notifications. Since it is not possible to change the Firebase key in the application, we were forced to make this part of the service proprietary.

Setup is done in the web configurator on your server: create a device mapping, scan the QR code in the app, and connect.
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FEATURES (WITH YOUR SERVER)
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Incoming calls (push wake)
• Battery-friendly mode — no permanent connection required
• Reliable wake on incoming calls via Firebase push
• Full-screen and lock-screen incoming call UI
Outgoing calls
• Stay connected and dial PBX extensions or external numbers
• Built-in keypad, redial, DTMF for IVR
During a call
• Mute, speaker, earpiece, wired headset, Bluetooth
• Hold, resume, blind transfer
• Optional local call recording
• Call history and missed-call notifications
Other
• QR code provisioning
• Organization branding from your server
• English and Russian UI
• Optional Android Telecom / system call integration
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REQUIREMENTS
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• Your own hosted SIP2GO gateway (mandatory)
• Android 8.0 or later
• Internet access to your gateway URL
• Google Play services (for push wake)
• Microphone permission
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WHO IS THIS FOR?
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IT teams, integrators, and businesses that run their own telephony infrastructure and want a secure Android extension connected through a gateway they control — not a consumer VoIP app from the Play Store.
Server source and documentation: provided by your SIP2GO deployment or vendor. You can get information about sip2go server on the official site s2g.uz.
Do not install this app unless you already have, or plan to deploy, the SIP2GO server component yourself.