At 4D, our mission is to provide you with the most robust and modern tools for your applications. To do that, we sometimes have to let go of the past to make room for the future.
As announced two years ago, the Legacy Network Layer (a technology that has served us well for over 30 years) was officially deprecated. Today, we are taking the final step: starting with 4D 21 R3, the Legacy layer has been completely removed.
But this isn’t just about removing old code; it’s about ensuring your applications automatically benefit from the speed, security, and stability of our modern network stacks: ServerNet and QUIC.

Seamless Transition

We’ve designed this transition to be as smooth as possible. 4D now handles the choice of the best network layer for you automatically based on your project type.
Here is how the logic works in the latest version:

• New Projects: When you create a new Project, 4D defaults to QUIC. This is our most advanced layer, offering superior stability and performance, especially on unstable networks.
• New Binary Databases: Since binary databases do not support QUIC, they will default to ServerNet, providing a high-performance, modern alternative to the old protocol.
• Opening Existing Applications: If you open an existing application (Project or Binary) that was still configured to use the “Legacy” layer, 4D will automatically upgrade the setting to ServerNet.

What do you win?

Upgrading to modern layers isn’t just a requirement; it’s a major upgrade for your users and your infrastructure.

With ServerNet, you gain access to:

• Preemptive processes: Maximize your server’s multi-core power.
• Sleep Mode support: Better handling of client machines going to sleep.
• Single Sign-On (SSO): Seamless authentication for your users.
• Native Encryption: Secure your data transmissions out of the box.

With QUIC, you get all the benefits of ServerNet, plus:

• Network Switching Support: Stay connected even when moving from Wi-Fi to 4G/5G.
• Resilience to Latency: QUIC is specifically designed to perform better on unstable or high-latency networks.

What do you need to do?

To ensure your transition is successful, please verify your network and firewall configurations.

For using QUIC:

• Just make sure your firewall allows UDP port 19813, or the one you have defined.

For using ServerNet:

• Make sure your firewall allows TCP ports 19813 and 19814.
• If you have modified the default port (19813), ensure that your custom port and the following one (+1) are open for TCP connections.
• We also recommend allowing UDP 19813 to enable server broadcasting and automatic detection.

The Final Step: It’s Time to Go Project!

While ServerNet is a fantastic modern alternative for binary databases, QUIC represents the gold standard of 4D networking. Because QUIC is exclusively available for projects, there has never been a better time to convert your binary databases to project mode.

By moving to project mode, you don’t just unlock QUIC; you embrace the full power of modern 4D development, including source control (Git), class-based programming, ultimate network resilience and so on.

We are excited to see your applications running faster and more securely on these modern foundations!

As always, feel free to join the discussion on the 4D Forums.