[FEAT] Replace custom NAT/LAN implementation with Iroh for reliable P2P connectivity

[daniil-verba]

🚀 [FEAT] Replace custom NAT/LAN implementation with Iroh for reliable P2P connectivity

📌 Current Limitations

Our current custom NAT/LAN implementation (src/network/lan.rs & src/network/beacon_client.rs) has critical limitations:

• Fails to reliably establish connections with the Beacon node.
• Lacks support for IPv6 and modern NAT traversal techniques.
• Results in frequent connection timeouts in real-world network environments (e.g., behind strict firewalls).

🌟 Proposed Solution

Replace the custom implementation with Iroh — a battle-tested, production-ready P2P networking library.

Why Iroh?

• ✅ Built-in NAT traversal (UPnP, STUN, TURN, and relay fallbacks).
• ✅ Zero-config Local Area Network (LAN) discovery.
• ✅ Production-ready and actively maintained by the team behind n0-computer.

🔧 Implementation Plan

1. Refactor custom NAT/LAN code:

   • Rewrite/replace logic in src/network/lan.rs
   • Rewrite/replace logic in src/network/beacon_client.rs

2. Integrate Iroh:

   # Cargo.toml
   [dependencies]
   iroh = "0.21" # (or latest stable version)

3. Adapt the API:

   • Map undertow-protocol's peer discovery to Iroh's Node API.
   • Implement connection fallbacks.

⚠️ Potential Challenges

• API Compatibility: Iroh is heavily async/await based, while parts of our current network code are synchronous. We will need to refactor the core networking layer to be fully async.
• Dependency Size: Iroh adds some overhead to the binary size, but this is an acceptable trade-off for massive gains in reliability.

💡 How You Can Help

This is a great task for a first-time contributor! We need help with:

• Research/Testing: Test Iroh in different NAT scenarios and provide test cases.
• Refactoring: Adapt src/network/mod.rs (and related files) to Iroh's API.
• Documentation: Update README.md with the new connectivity guarantees and setup instructions.

🙏 Why This Matters

This change will solve the #1 pain point of the project. With Iroh, undertow-protocol will finally work reliably in real-world networks, making it truly viable for decentralized applications. Let's build something that just works! 🚀

✅ Checklist Before Merging

• All connectivity tests pass
• No breaking changes to the public API (or clearly documented if there are)
• Documentation updated
• Benchmark comparison (latency/throughput) completed

💬 Discussion

What do you think about this approach?

1. Should we fully replace the current implementation, or keep it as a fallback for now?
2. We can break this down into smaller sub-issues to make it easier to tackle step-by-step!