A fundamental networking myth has been busted: TCP and QUIC are equally good for punching through NATs in decentralized webs.
April 16, 2026
Original Paper
Large-Scale Measurement of NAT Traversal for the Decentralized Web: A Case Study of DCUtR in IPFS
arXiv · 2604.12484
The Takeaway
For years, the decentralized web community has operated under the 'gospel' that UDP (and thus QUIC) is superior to TCP for NAT traversal. This empirical study of 4.4 million attempts on the IPFS network shows that their success rates are actually statistically indistinguishable. This is a massive 'paradigm challenge' for P2P networking. Engineers can stop over-complicating their stacks to favor UDP and can return to the stability of TCP without losing connectivity. This simplifies the development of decentralized apps and challenges the design of current P2P protocols. It’s a rare case where the data proves that the simpler path was the right one all along.
From the abstract
The promise of decentralized peer-to-peer (P2P) systems is fundamentally gated by the challenge of Network Address Translation (NAT) traversal, with existing solutions often reintroducing the very centralization they seek to avoid. This paper presents the first large-scale measurement study of a fully decentralized NAT traversal protocol, Direct Connection Upgrade through Relay (DCUtR), within the production libp2p-based InterPlanetary File System (IPFS) network. Drawing on over 4.4 million trav