How to Configure a Custom TURN Server for P2P Sharing

WebRTC is the magical technology that powers the instant, serverless file sharing behind Textunnel. For about 85% of users, WebRTC successfully establishes a Direct connection (via STUN) that allows files to fly across your local Wi-Fi network at blazing speeds.

But what happens if you're trying to share files across a strict corporate firewall, or a complex symmetric NAT environment where STUN hole-punching fails?

You need a TURN Server—a relay server that bounces your encrypted files from Device A to Device B.

While Textunnel provides a free, built-in TURN server as a fallback, we know that power users, homelab enthusiasts, and corporate security teams demand total control over their data flow.

The "Zero Trust" Solution: Custom TURN Servers

Today, we're thrilled to introduce a feature highly requested by the networking community: Custom TURN Server Support.

Custom TURN Server UI

Why Use a Custom TURN Server?

1. Uncapped Speeds: Public TURN servers are often rate-limited to 1-2 MB/s to prevent abuse. By running your own Coturn server on a high-bandwidth VPS (like AWS, DigitalOcean, or a local Homelab), you can relay massive files at Gigabit speeds.
2. Absolute Privacy: Even though all Textunnel transfers are End-to-End Encrypted (E2EE), relaying your data through your own server guarantees that 100% of the network packets remain within your controlled infrastructure.
3. Reliability: Self-hosted TURN servers ensure your connection never drops, even during public infrastructure outages.

How to Set It Up

1. Deploy Coturn: If you don't have one, spin up a lightweight Linux VPS and install coturn.
2. Open Textunnel Settings: Click the Settings gear icon in Textunnel.
3. Expand Advanced Settings: Click "Advanced: Custom TURN Server".
4. Enter Credentials: Input your turn:your-domain.com:3478 URL, along with your secure username and password.
5. Save: Click Save. Your browser will instantly prioritize your custom infrastructure for all future connections!

Real-Time Connection Monitoring

How do you know if your files are traveling via Direct P2P or bouncing through your new TURN server?

We've added a real-time connection diagnostic badge directly into the Device List. When you connect to a device, you will see a glowing green DIRECT badge (if local hole-punching succeeds) or a yellow RELAYED badge (if it falls back to your TURN server).

Stop relying on black-box tools. Take control of your network with Textunnel.