Networking in a Trustless Distributed System

From Client-Server to Peer-to-Peer: How Ethereum's Network Actually Works

Every developer knows how the internet works: a client makes a request, a server responds. But what happens when there is no server — no trusted authority to route your messages, verify your identity, or decide who gets to participate? This is the world trustless distributed systems like Ethereum, Bitcoin etc live in.

This talk takes developers on a ground-up tour of peer-to-peer networking in a trustless distributed system. We start by contrasting familiar client-server architectures with the different assumptions of a decentralized network — and unpack why those differences make networking problems different in decentralized systems. We then explore the core technologies that Ethereum specifically uses to solve these problems: peer discovery via distributed hash tables, distributed queue like message passing, modern transport with QUIC, and newer ideas like fault-tolerant data propagation via erasure-coded broadcast. We also cover SSZ — Simple Serialize — a novel on-the-wire serialisation mechanism invented by Ethereum developers that is purpose-built for broadcasting critical data on the wire.

We look at libp2p which is a modular networking stack on which Ethereum is built upon. We cover concrete examples on how peer to peer networking is used in Ethereum including aspects like attestation broadcast and binary blob data broadcast.

We end the talk covering some of the unique challenges faced in peer to peer networking in systems like Ethereum and how they are being approached.

1. How networking in a trustless distributed system like Ethereum works.

2. We learn about peer to peer networking and the challenges involved with it.

3. We cover interesting technical topics like distributed queues, erasure coded broadcast, QUIC, peer discovery with distributed hash tables etc.

4. We briefly talk about SSZ which is a novel on the wirte serde mechanism invented by Ethereum developers.

5. We talk about specific p2p libraries like libp2p

6. We cover examples on p2p networking in Ethereum like attestation broadcast, block broadcast and opaque binary data broadcast

7. We cover some of the unique challenges that a protocol like Ethereum faces w.r.t networking.