Hard Numbers: HTTP/2 vs UDP Overlay for Agent Communication

Source: Dev.to

Test Environment

• Locations: Two machines on different continents – GCP us-east1 (South Carolina) and europe-west1 (Belgium).
• Round‑trip time (RTT): ~85 ms.
• Runs: 100 per test, median reported.
• Benchmark type: Real‑world workloads, no synthetic benchmarks.

Connection Setup

Orchestrator Overhead

When dispatching tasks to 50 agents:

• HTTP/2: ~8.75 seconds of pure overhead.
• Pilot: ~750 ms of overhead.

Message Latency

Latency is dominated by the 85 ms network RTT; protocol overhead is negligible.

For the typical payload sizes agents actually send, the difference is irrelevant.

Memory Usage at Scale

• 100 simultaneous peer connections:
  • HTTP/2: 240 MB RSS.
  • Pilot: 24 MB RSS.

All Pilot connections share a single UDP tunnel, eliminating a separate TCP socket and TLS session per peer. On resource‑constrained VMs this translates to running 100 agents with Pilot versus only 10 agents with HTTP/2.

NAT Traversal

• Scenario: One agent behind Cloud NAT.
• HTTP/2: Requires a relay proxy, adding 145 ms to setup and 32 ms to each message, reducing throughput by 31 %.
• Pilot: Hole‑punches through NAT, establishing a direct tunnel. After the punch, overhead is +7 ms setup and +2 ms per message, with only 4 % throughput loss.

Conclusion

The decision isn’t “HTTP or Pilot.” It’s:

• Use HTTP/2 where direct connectivity is guaranteed.
• Use Pilot where NAT, corporate boundaries, or other network constraints exist.

For agents spanning diverse networks, the “must‑use” case applies to ≈ 88 % of deployments.

References

• Benchmarking Agent Communication: HTTP vs. UDP Overlay
• Connect AI Agents Behind NAT Without a VPN
• pilotprotocol.network
• GitHub – Pilot Protocol