asl3-chan-svx

chan_svx is an Asterisk channel driver for AllStarLink 3 that connects directly to a SvxLink SVXReflector.

Unlike traditional solutions that rely on a USRP bridge, chan_svx speaks the SVXReflector protocol natively, providing:

• Lower latency
• Simpler system architecture
• A single Opus transcoding step
• Reduced CPU and memory usage
• Direct integration with app_rpt

This allows SVXReflector talk groups to be used directly from AllStarLink without an intermediate USRP connection.

Features

• Native SVXReflector connectivity
• Direct integration with AllStarLink 3 (app_rpt)
• SVXReflector v2 protocol support (HMAC-SHA1)
• Configurable jitter buffer
• Adjustable RX/TX gain
• Optional RX/TX AGC
• Support for x86-64 and ARM64 (Raspberry Pi)

Source code is private.

Bug reports and support requests: bjorne@sa7aux.se

Requirements

• Debian 12 (Bookworm) or Debian 13 (Trixie)
• AllStarLink 3 (asl3-asterisk) already installed
• Access credentials for an SVXReflector

Download

Clone the repository:

git clone https://github.com/<your-repository>/asl3-chan-svx.git
cd asl3-chan-svx

Choose the Correct Package

Verify your Debian release:

. /etc/os-release
echo $VERSION_CODENAME

Verify your CPU architecture:

dpkg --print-architecture

Platform	Package
Debian 13 (Trixie), x86-64	debs/asl3-chan-svx_0.3.2~trixie_amd64.deb
Debian 13 (Trixie), ARM64 (Raspberry Pi OS Trixie)	debs/asl3-chan-svx_0.3.2~trixie_arm64.deb
Debian 12 (Bookworm), x86-64	debs/asl3-chan-svx_0.3.2~bookworm_amd64.deb
Debian 12 (Bookworm), ARM64 (Raspberry Pi OS Bookworm)	debs/asl3-chan-svx_0.3.2~bookworm_arm64.deb

Only 64-bit platforms are supported.

Installation

Install the package that matches your operating system and architecture:

sudo apt install ./debs/asl3-chan-svx_0.3.2~<os>_<arch>.deb

Required dependencies (asl3-asterisk, libopus0, and libssl3) will be installed automatically.

Configuration

1. Create svx.conf

Create /etc/asterisk/svx.conf and configure:

• Reflector hostname
• Port
• Callsign
• Password
• Talk group

Optional settings:

• tx_hold
• jitter
• rx_gain
• tx_gain
• rx_agc
• tx_agc

2. Enable the Channel Driver

Edit /etc/asterisk/modules.conf and enable the module:

load = chan_svx.so

If a line already exists as:

;load = chan_svx.so

remove the leading semicolon.

3. Configure app_rpt

Edit /etc/asterisk/rpt.conf and set:

rxchannel = SVX/<section>

where <section> matches the section name in svx.conf.

4. Restart Asterisk

sudo asterisk -rx "core restart now"

5. Verify Operation

Check the driver status:

sudo asterisk -rx "svx show"

A successful connection will display reflector and talk group information.

Documentation

A complete installation and configuration guide is included with the package:

/usr/share/doc/asl3-chan-svx/INSTALL.md

The package post-install script (postinst) also displays the required setup steps after installation.

Compatibility

chan_svx implements the SVXReflector v2 protocol (HMAC-SHA1).

Reflectors that provide v2 compatibility can be used even if their SvxLink nodes normally operate using v3/TLS.

Notes

• Reflector logins must use an upper-case callsign.
• SVXReflector validates callsigns case-sensitively.
• The package version should match the installed AllStarLink 3 release.