JioFiber SIP B2BUA

A lightweight, native SIP Back-to-Back User Agent (B2BUA) that bridges JioFiber VoIP (Jio IMS) to any standard SIP softphone — over LAN, Tailscale, ZeroTier, WireGuard, or any VPN.

No Docker. No Asterisk. No cloud. Runs as a single binary.

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Features

• Zero-dependency binary — single executable for Windows, Linux x86_64, and Linux ARM64
• Embedded Native OTP Provisioner — automatically requests OTP and provisions credentials directly from your Jio router without needing Python
• Dual Transport Support (UDP & TLS):
  • Local Listener: Standard UDP (5061) + Encrypted TLS (5062 / LOCAL_TLS_PORT) for softphones
  • Upstream Transport: TLS v1.2 (5068) to Jio IMS router/ONT
• Local TLS Auto Certificate Generator: Automatically creates 10-year 2048-bit RSA self-signed cert.pem and key.pem files on disk for encrypted softphone signaling
• Strict Port Binding: Binds directly to 5061 and 5062 and exits immediately if either port is in use
• Automatic SIP registration with Jio IMS over TLS with self-healing credential rotation recovery
• Full call flow bridging — outgoing calls, incoming calls, BYE, CANCEL, re-INVITE
• Multi-network support — LAN, Tailscale, ZeroTier, WireGuard, OpenVPN
  • Per-call dynamic source IP detection using OS kernel routing table (getsockname connect trick)
  • Solves one-way audio and call teardown failures across VPN overlays
  • Zero static IP configuration needed
• Robust Teardown Handling — clean SIP CANCEL & BYE handling without double-hangup assertions
• PUBLISH / presence passthrough for softphone status
• Zero SSD wear logging — 512 KB RAM ring-buffer + Windows Named Pipe (\\.\pipe\jio_b2bua_logs)
• Codec support — AMR-NB (octet-aligned mode-set), PCMA, PCMU, telephone-event DTMF

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Performance & Architecture Improvements vs Precursor Projects

Compared to earlier Python/Asterisk/Docker implementations (such as jiofiber-sip-proxy, JFC-microsip, and Asterisk bridge setups), this native C++ B2BUA delivers significant performance, resource, and operational enhancements:

Performance & Feature Metric	Precursor Projects (Python / Docker / Asterisk)	Native C++ B2BUA (sipserver)
Memory Footprint (RAM)	~250 MB – 1.5 GB (Python VM, Docker overhead, Asterisk daemon)	~8 MB – 15 MB RAM (Ultra-lightweight native process)
Packet Forwarding Latency	~20 ms – 50 ms (Python GIL contention & virtual container network bridges)	< 1 ms Sub-millisecond latency (Native C++ multi-threaded PJSIP stack)
Binary & Dependencies	Requires Python 3, Pip packages, Docker Engine, or full Asterisk stack	Zero dependencies — Single ~1.7 MB compiled binary
Provisioning Flow	External Python scripts or manual HTTP web forms	100% Native Embedded C++ Provisioner (OTP request & credential extraction inside binary)
Disk & SSD Impact	Continuous disk IO log writes and container storage wear	Zero SSD Wear — 512 KB RAM ring-buffer + Windows Named Pipe stream
VPN Overlay Routing	Static IP binding (causes 1-way audio / disconnects over Tailscale/WireGuard)	Dynamic OS Kernel Routing (getsockname) — dynamic multi-interface IP detection
Local Softphone Security	Unencrypted UDP signaling only	Dual Transport: UDP (5061) + Encrypted TLS (5062) with auto-generated 2048-bit RSA certificates
Port Collision Handling	Silent failures or background process hangs	Strict Port Binding — instant fail-fast detection if port 5061/5062 is occupied

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Quick Start

1. Download a pre-built binary / 1-Click Installer

Go to Releases and download the 1-click installer or standalone binary for your target platform:

Platform	Download Link	Package Name	Type / Notes
Windows x64 64-bit (1-Click Installer)	🚀 Download 64-bit Setup (JioFiber_B2BUA_Setup_x64.exe)	JioFiber_B2BUA_Setup_x64.exe (228 KB)	⚡ 1-Click 64-bit Windows Installer (Auto-configures Firewall, Service & Shortcuts)
Windows x86 32-bit (1-Click Installer)	🚀 Download 32-bit Setup (JioFiber_B2BUA_Setup_x86.exe)	JioFiber_B2BUA_Setup_x86.exe (188 KB)	⚡ 1-Click 32-bit Windows Installer (Compatible with legacy 32-bit Windows systems)
Windows Portable	📥 Download b2bua_msvc.exe	b2bua_msvc.exe (1.7 MB)	✅ Zero-dependency standalone MSVC binary
Linux 1-Click Script (x86_64 / ARM64)	🐧 Download install_linux.sh	install_linux.sh (2.5 KB)	⚡ 1-Click Linux Installer (Auto-detects Arch, Firewall, Service)
Linux x86_64 (AppImage)	🐧 Download JioFiber_B2BUA-x86_64.AppImage	JioFiber_B2BUA-x86_64.AppImage (835 KB)	⚡ 1-Click Portable Linux AppImage
Linux x86_64 Standalone	📥 Download b2bua-linux-amd64	b2bua-linux-amd64 (1.9 MB)	✅ Pre-built Linux binary
Linux ARM64	📥 Download b2bua-linux-arm64	b2bua-linux-arm64 (1.8 MB)	✅ Pre-built for Raspberry Pi / Routers
Linux RISC-V 64	b2bua (linux-riscv64)	b2bua	🔧 Build from source via python src/build_riscv64.py

Windows on ARM (Snapdragon X Elite / Surface Pro ARM / Windows 11 ARM64): Windows 11 ARM64 includes Microsoft's Prism x64 emulation engine — the standard b2bua_msvc.exe (x64) runs on all Windows ARM devices with near-native speed and zero configuration needed. A native ARM64 build script (src/build_win_arm64.py) is also provided if you have the MSVC ARM64 cross-compile toolchain installed.

2. Provision credentials (one-time)

The provisioner is built directly into the binary. Simply launch b2bua and it will automatically prompt for your Jio router IP and OTP if .env does not exist:

• When launched for the first time, it prompts for your Jio router IP (usually 192.168.29.1).
• Enter the OTP sent to your registered Jio mobile number.
• Prompt for Local TLS Certificate Setup:
  • Option 1 [Default]: Generate a brand new TLS certificate pair (cert.pem & key.pem).
  • Option 2: Keep & use existing cert.pem from disk.
  • Option 3: Disable Local TLS (UDP port 5061 only mode).
• It automatically whitelists your device, fetches your SIP credentials, and saves .env.

Installing Certificate on Phone: Copy cert.pem to your phone. Select it in Linphone under Settings -> Network -> Advanced / TLS -> Root CA or install it into your phone's System CA Certificate Store to enable Secured 🔒 UI badge.

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How to Transfer & Install TLS Certificate (cert.pem) on Phone / Softphone

When Local TLS is enabled on port 5062, b2bua auto-generates cert.pem on disk. Transfer and install cert.pem to your phone to get the Secured 🔒 encrypted status badge:

📱 Method 1: Transferring cert.pem to Your Phone

• Local Web Transfer (Fastest): Run a quick local web server in your terminal folder:

  python -m http.server 8000

  On your phone browser, navigate to http://<YOUR-PC-IP>:8000/cert.pem and download cert.pem.
• Alternative Methods: Copy cert.pem via USB cable, AirDrop, Google Drive, Email, or Local Storage.

🤖 Android (Linphone & System Store)

1. Inside Linphone App:
   • Open Linphone -> Settings ⚙️ -> Network -> TLS / CA Certificates.
   • Tap Root CA -> Browse and select cert.pem.
   • Set Account Transport to TLS with port 5062.
2. Android System CA Store (Optional):
   • Open Phone Settings -> Security & Privacy -> More Security Settings -> Encryption & Credentials.
   • Tap Install a Certificate -> CA Certificate -> Select cert.pem.

🍏 iOS / iPhone (Linphone & Profile Trust)

1. AirDrop or download cert.pem to the Files app on your iPhone.
2. Tap cert.pem -> Notice pop-up: "Profile Downloaded".
3. Open iPhone Settings -> Tap Profile Downloaded -> Tap Install (Enter passcode).
4. Enable Full Trust: Go to Settings -> General -> About -> Certificate Trust Settings -> Enable Full Trust for JioFiberB2BUA.
5. Open Linphone -> Settings -> Network -> Set Transport to TLS (Port 5062).

💻 Windows (MicroSIP & Linphone Desktop)

• MicroSIP: Copy cert.pem into your MicroSIP folder. In MicroSIP Settings -> Network -> Check TLS and select cert.pem as CA file.
• Linphone Desktop: Open Preferences -> Network -> Advanced -> Select cert.pem as Root CA.

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3. Run

Windows — 1-Click Setup (JioFiber_B2BUA_Setup.exe): When running JioFiber_B2BUA_Setup.exe, you can choose between two modes:

1. Service Mode [Default]: Installs and starts JioFiberB2BUA as an automatic Windows background service that starts on boot.
2. Non-Service / Interactive Console Mode: Runs b2bua_msvc.exe directly in a visible command window with live log output.

Windows (Manual Batch Scripts):

• Interactive Console Mode: Double click run_windows.bat
• Background Service Mode: Run install_windows_service.bat (as Administrator)
• Uninstall Service: Run uninstall_windows_service.bat (as Administrator)

Linux — 1-Click Systemd Service Installer: Run this single command on any Linux terminal to install & start jiofiber-b2bua as an automatic background service (auto-starts on boot):

curl -sSL https://raw.githubusercontent.com/sidhantjohnaind/sipserver/master/install_linux.sh | sudo bash

Linux — 1-Click Portable AppImage:

chmod +x JioFiber_B2BUA-x86_64.AppImage
./JioFiber_B2BUA-x86_64.AppImage

Linux Service Management:

• Status Check: sudo systemctl status jiofiber-b2bua
• View Live Logs: sudo journalctl -u jiofiber-b2bua -f
• Uninstall Service: sudo ./uninstall_linux_service.sh

Freeing Busy Ports (5061 / 5062): Both run_windows.bat and run_wsl.sh automatically terminate any stale background processes occupying ports 5061 or 5062 before starting. To manually free ports 5061 and 5062 at any time:

• Windows: Double-click kill_ports.bat
• Linux / WSL: Run chmod +x kill_ports.sh && ./kill_ports.sh

4. Configure your softphone

Setting	Value
SIP Server / Domain	<your-pc-ip>:5061 (UDP) or <your-pc-ip>:5062 (TLS)
Transport	UDP or TLS
Username	any (e.g. 101)
Password	any

TLS / Linphone Note: When using TLS transport on port 5062, Linphone displays Secured 🔒 once cert.pem is imported into Linphone or your phone's Trust Store.

Tailscale users: Use your Tailscale IP (e.g. 100.x.x.x:5061 or 100.x.x.x:5062) as the SIP server in your softphone. The B2BUA automatically detects and uses the correct Tailscale interface.

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Architecture

Softphone (SIP/UDP or SIP/TLS)
  ↕  UDP port 5061 / TLS port 5062
[B2BUA]  ←── .env credentials
  ↕  TLS port 5068
Jio IMS / ONT (192.168.29.1)
  ↕
PSTN / Phone Numbers

The B2BUA acts as a full SIP proxy:

• Listens on UDP 5061 and TLS 5062 for local softphones
• Registers upstream with Jio IMS over TLS 5068
• Bridges all call legs transparently
• Rewrites Contact and SDP headers per-call to match the correct network interface

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Building from Source

Note: Stock PJSIP 2.15.1 is used with two small Jio IMS compatibility patches provided in patches/ (applied automatically using python apply_patches.py). All B2BUA proxy logic is contained in src/b2bua.cpp.

Step 1 — Download stock PJSIP 2.15.1

Download the official release and extract it:

# Option A: GitHub release
wget https://github.com/pjsip/pjproject/archive/refs/tags/2.15.1.tar.gz
tar -xzf 2.15.1.tar.gz
mkdir -p third_party
mv pjproject-2.15.1 third_party/

# Option B: Direct source zip (Windows)
# Download from: https://github.com/pjsip/pjproject/releases/tag/2.15.1
# Extract to: third_party\pjproject-2.15.1\

Step 2 — Apply Jio IMS Compatibility Patches

Run the automated cross-platform patch script once after extracting PJSIP:

python apply_patches.py

This applies two small compatibility patches to PJSIP 2.15.1:

1. opencore_amr.c: Enforces octet-aligned AMR, sets bitrate to 12.2kbps (Mode 7), echoes mode-set in SDP, and disables VAD for Jio IMS.
2. stream.c: Enables trace logging for jitter buffer frame retrieval.

Step 3 — Build Binaries & 1-Click Installers

Windows x64 64-bit Setup Installer & Portable Binary:

python src/build_msvc_pjsip.py    :: Compiles b2bua_msvc.exe
python src/build_installer.py     :: Compiles JioFiber_B2BUA_Setup_x64.exe

Output: bin/windows-x64/b2bua_msvc.exe & JioFiber_B2BUA_Setup_x64.exe

Windows x86 32-bit Setup Installer:

python src/build_installer_x86.py :: Compiles JioFiber_B2BUA_Setup_x86.exe

Output: JioFiber_B2BUA_Setup_x86.exe

Windows ARM64 (MSVC cross-compile):

python src/build_win_arm64.py

Output: bin/windows-arm64/b2bua_win_arm64.exe

Linux x86_64 Binary & Portable AppImage:

python3 src/build_wsl.py
python3 scripts/build_appimage.py

Output: bin/linux-amd64/b2bua & JioFiber_B2BUA-x86_64.AppImage

Linux ARM64 (cross-compile):

# Install cross-compiler first:
sudo apt install gcc-aarch64-linux-gnu g++-aarch64-linux-gnu

python3 src/build_arm64.py

Output: bin/linux-arm64/b2bua

Linux RISC-V 64-bit (cross-compile):

# Install cross-compiler:
sudo apt install gcc-riscv64-linux-gnu g++-riscv64-linux-gnu

python3 src/build_riscv64.py

Output: bin/linux-riscv64/b2bua

What the build scripts do

The build scripts (src/build_*.py and scripts/build_*.py) compile PJSIP 2.15.1 source alongside src/b2bua.cpp and src/installer.cpp, packing everything into standalone binaries, 1-click Windows installers, and Linux AppImage packages. No system PJSIP install is needed.

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Configuration Reference (.env)

File Storage Locations (.env, cert.pem, key.pem)

Depending on how you run JioFiber B2BUA, your configuration (.env) and TLS certificate files (cert.pem, key.pem) are stored in the following locations:

Environment / Mode	Configuration (.env) & TLS Certificate Storage Path	Notes
Windows Service Mode	C:\Program Files\JioFiberB2BUA\.env C:\Program Files\JioFiberB2BUA\cert.pem C:\Program Files\JioFiberB2BUA\key.pem	⚡ Setup Installer automatically copies existing .env & cert files to C:\Program Files\JioFiberB2BUA\ during installation
Windows Portable / Console	Same directory as b2bua_msvc.exe (e.g. C:\YourFolder\.env)	Reads .env & certs from the local execution folder
Linux Systemd Service	Directory where install_linux.sh was executed (e.g. /opt/jiofiber-b2bua/.env)	WorkingDirectory=$SCRIPT_DIR configures systemd to use local folder
Linux Portable AppImage	Same working directory where ./JioFiber_B2BUA-x86_64.AppImage is launched	Reads .env & certs from the execution directory

.env Variable Reference

Variable	Description	Example / Default
IPV4_ADDRESS	Your PC's LAN IP	192.168.29.195
LOCAL_PORT	UDP SIP port for softphones	5061
LOCAL_TLS_PORT	Local TLS SIP port for softphones	5062
ENABLE_LOCAL_TLS	Enable local TLS listener	1 (or 0 to disable)
TLS_CERT_FILE	Path to TLS Certificate file	cert.pem
TLS_KEY_FILE	Path to TLS Private Key file	key.pem
GENERATE_NEW_TLS_CERT	Force new cert pair on startup	0 or 1
TLS_PORT	TLS port to Jio router	5068
RTP_PORT	Base RTP port	52000
PUBLIC_ID	Your Jio SIP URI	sip:+91XXXXXXXXXX@br.wln.ims.jio.com
SIP_AUTH_USER	SIP auth username	91XXXXXXXXXX@br.wln.ims.jio.com
SIP_PASSWORD	SIP password	xxxxxxxxxx
SIP_REALM	SIP auth realm	br.wln.ims.jio.com
REGISTRAR_HOST	Jio router IP	192.168.29.1
MAX_CALLS	Max simultaneous calls	4
LOG_LEVEL	PJSIP log verbosity (1–5)	5
TLS_VERIFY	Verify TLS cert (0=skip)	0

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Viewing Logs

Windows:

view_logs.bat

Linux:

journalctl -u jiofiber-b2bua -f

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Supported Softphones

Tested and working:

• Linphone (Android / iOS / Desktop) — Supports TLS port 5062 for Secured 🔒 status
• Sipnetic (Android)
• MicroSIP (Windows)
• PhonerLite (Windows)
• Zoiper (Android / iOS)
• Asterisk (as upstream SIP trunk)

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Acknowledgements

This project stands on the shoulders of prior reverse-engineering and open-source telephony work. Huge thanks to:

• JFC-Group — the community that first mapped out how JioFiber's JUICE/IMS client provisions and registers. In particular JFC-microsip (the provisioning/config flow that jfc_configure.py derives from) and the JFC pjproject work that proved the patch path. Without their groundwork the +sip.instance shape, the OTP whitelist flow, and the rotating-password behaviour would have stayed a black box.
• ankurpandeyvns/jiofiber-sip-proxy — Special thanks to Ankur Pandey for reverse-engineering the Jio router HTTP provisioner API, OTP authorization flow, and SIP IMS auth parameters.
• sivatheja10/jiofiber-bridge — Special thanks to Siva Theja for initial SIP bridge research and protocol flow analysis.
• pjproject / PJSIP — the SIP/media stack the B2BUA is built on; the patches here are small deltas against it.
• opencore-amr — the AMR-NB/AMR-WB codec that makes IMS audio interoperate with plain softphones.
• Tailscale / WireGuard — the overlay network glue enabling remote calling.

This repo's contribution is the native end-to-end integration — a single-binary self-healing B2BUA that solves inbound call routing, correct AMR mode-set echo, automatic multi-interface RTP routing (Tailscale/LAN), and zero-SSD-wear RAM logging.

If you built on something here or spot missing attribution, please open an issue or PR.

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Disclaimer

This software interoperates with your own telephone line for personal use, the same way the official app on your own router does. It reimplements a client to a service you pay for. Check your provider's terms; you are responsible for how you use it. Provided as-is, no warranty. Not affiliated with, or endorsed by, any ISP or provider.

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License

MIT License — see LICENSE