2025-06-13 –, Side Stage - Cinema 6
How many nodes are in given network? A seemingly simple question with a more elusive answer than it seems. Different methodologies yield different results with implications for protocol design. Let's explore the hidden complexities.
How many nodes are really participating in a peer-to-peer network? The answer isn’t straightforward. Do we count unique IPs? IP+Port pairs? Node IDs? Peer IDs? ENRs? Each method provides a different perspective, and no single approach captures the full picture. Some count nodes by crawling the public DHTs, others analyze on-chain transactions, and some perform random key lookups—but each yields different results. And that’s just the server side—how do we detect clients interacting with the network?
But why does this matter? The total number of nodes influences critical decisions about protocol parameters, replication factors, and resource allocation. It affects estimates of network bandwidth usage and energy consumption. Understanding the true scale of a network is essential for making informed decisions about its infrastructure. This talk unpacks the surprising challenges of node counting.
Dennis is a software engineer at ProbeLab (formerly Protocol Labs). ProbeLab and hence Dennis focusses on internal network protocol logic, as well as cross-protocol interoperation and network architecture. Next to his work at ProbeLab, Dennis is an industrial PhD candidate at the University of Göttingen where he focusses on peer-to-peer network measurements and optimizations.