Overlay Subsystem — Technical Summary

Overview

The overlay subsystem implements stellar-core's peer-to-peer network layer. It manages TCP connections to other nodes, authenticates peers via ECDH+HMAC, floods broadcast messages (transactions, SCP messages) across the network, fetches missing data (tx sets, quorum sets) via anycast requests, and performs network surveys. The subsystem supports optional background thread processing for I/O-heavy operations (reads/writes on TCP sockets) to keep the main thread responsive.

Key Files