Modern networking in Firefox with Max Inden

Episode 11 – Modern networking in Firefox with Max Inden.

A conversation with Max Inden, Staff Software Engineer at Mozilla, about modernizing Firefox’s networking stack in Rust. We cover his work on the QUIC and HTTP/3 stack — improving UDP I/O, congestion control, and overall performance — and why QUIC matters as a fast, encrypted, and evolvable transport for HTTP/3, WebTransport, and beyond.

Learn more:

https://max-inden.de/ — Personal website of Max Inden https://max-inden.de/post/fast-udp-io-in-firefox/ — Fast UDP I/O for Firefox in Rust — by Max Inden https://archive.fosdem.org/2025/schedule/event/fosdem-2025-4229-getaddrinfo-sucks-everything-else-is-much-worse/ — getaddrinfo sucks, everything else is much worse — Talk by Valentin Gosu https://github.com/mozilla/neqo — Mozilla Neqo (HTTP/3 and QUIC stack) https://datatracker.ietf.org/doc/html/rfc9000 — RFC 9000 – QUIC: A UDP-Based Multiplexed and Secure Transport https://datatracker.ietf.org/doc/html/rfc9114 — RFC 9114 – HTTP/3 https://datatracker.ietf.org/doc/html/rfc9462 — RFC 9462 – Discovery of Designated Resolvers https://www.rfc-editor.org/rfc/rfc8484.html — RFC 8484 – DNS Queries over HTTPS (DoH) https://datatracker.ietf.org/doc/draft-ietf-happy-happyeyeballs-v3/ — Happy Eyeballs Version 3 (Draft) https://github.com/microsoft/msquic — Microsoft MsQuic https://developer.mozilla.org/en-US/docs/Web/API/WebTransport — WebTransport API documentation https://datatracker.ietf.org/wg/masque/about/ — MASQUE (Proxy) protocol introduction https://www.ietf.org/ — Internet Engineering Task Force (IETF) https://www.ietf.org/meeting/ — IETF Meetings

Rama

If you like this podcast you might also like our modular network framework in Rust: https://ramaproxy.org

Chapters

00:00 Intro 00:38 Introduction to Max Inden 03:27 Max Inden's Journey to Mozilla 06:32 The Role of IETF in Internet Design 09:42 QUIC and HTTP/3 in Firefox 12:27 Understanding HTTP/3 Upgrade Mechanisms 15:15 Challenges with UDP and Firefox's Networking Stack 18:15 Optimizing UDP I/O for Performance 21:36 Cross-Platform Performance Considerations 24:23 Network Drivers and Their Impact 27:18 Exploring Happy Eyeballs and Connection Strategies 30:07 WebTransport and Future of QUIC 32:56 Contributions to Firefox and Open Source 36:05 Happy Eyeballs and related 56:15 Github Git Hosting 57:24 Quic Usage within Firefox 01:03:02 Closing Thoughts and call to Action 01:06:44 Outro

Netstack.FM

More information: https://netstack.fm/#episode-11 Join our Discord: https://discord.gg/29EetaSYCD Reach out to us: [email protected]

Music for this episode was composed by Dj Mailbox. Listen to his music at https://on.soundcloud.com/4MRyPSNj8FZoVGpytj.