# Systems

rustunnel's internal architecture is divided into five systems:

- [Tunnel engine](tunnel-engine.md) — listener accept loop, connector reconnect loop, stream multiplexing, SOCKS5 proxy integration
- [TLS stack](tls-stack.md) — rustls configuration, certificate loading, identity validation
- [Framing protocol](framing-protocol.md) — binary frame format, serialization, partial read handling
- [SOCKS5 proxy](socks5-proxy.md) — RFC 1928 handshake, CONNECT support, target resolution
- [Credential generation](credential-generation.md) — self-signed CA and certificate generation with rcgen