AI Agent Networking in 2026: NAT Traversal, Encrypted Tunnels, and Why MCP Needs a Transport Layer

If you're building multi-agent systems in 2026, you've probably run into a version of this problem: your agents work great in local dev, but the moment they're on different machines, different clouds, different networks, different NAT configurations so they can't find each other, can't connect reliably, or you end up bolting on ngrok, a message broker, or a cloud relay just to get two agents talking. This isn't a code problem. It's a networking problem. And the ecosystem's two biggest agent prot