freesbc

Name: freesbc
Author: rasonyang

by rasonyang

FreeSBC is a session border controller written in Go that sits on the public internet in front of a FreeSWITCH or Asterisk phone system. It relays SIP and media traffic, bridges WebRTC, and blocks scanning and brute-force attempts so the phone system itself stays on a private network.

Hidden gemIt's a single Go binary that sits in front of FreeSWITCH or Asterisk, so the PBX stays off the public internet. It handles SIP proxying, RTP/SRTP relay, WebRTC and basic attack protection. The install, docs, tests and published load figures make it look like a real, working tool, not a demo. Best for small VoIP operators exposing FreeSWITCH or Asterisk to the internet.

New and promisingUnder two months old. Expect rough edges and fast changes.

View on GitHub

Stars: 296 +6 a day, est.
Licence: Apache-2.0
Runs on: A small server
Setup: Technical
Language: Go
Age: 52 days

What you can do with it

Put a FreeSWITCH or Asterisk server behind a single public address so it is never exposed directly
Let desk phones, browser softphones and carriers connect over UDP, TCP, TLS or WebRTC
Block SIP scanners and registration brute-force attempts, and watch live calls in the built-in web admin page

Make money with it

An IT freelancer could offer secured, managed VoIP setups for small businesses, using FreeSBC as the protective front end for their FreeSWITCH or Asterisk systems.

An idea, not financial advice. Check the licence before charging for anything built on it.

Ways a business could use it

Run a hosted or in-house phone system for a small call centre without paying for a commercial session border controller
Offer remote staff browser-based calling through a secured public entry point while keeping the main phone system private

Can you use it commercially?

Free to use, change and sell, including in paid products. Keep the copyright notice.

Not legal advice. Read the project's licence file before building a product on it.

Getting it running

Install the single binary with the provided curl install script (Linux or macOS), then create a YAML config with `freesbc init` and start it with `freesbc run`, optionally as a systemd service.

Follow the official instructions in the project README.

Things to check

Needs a working FreeSWITCH or Asterisk setup and telephony knowledge
Misconfiguration on a public-facing server is a security risk, so the docs must be read first
No transcoding, no clustering and all state (including bans) is held in memory

Checked 01 Nov 2026. Summary drafted by AI from the project's README.