Introduction
High Performance Browser Networking was published in 2013, with updates through 2015-2016. While the fundamental principles of network performance remain timeless, specific protocols and technologies have evolved significantly. This guide helps you navigate which chapters are still directly applicable and which should be read for conceptual understanding.
Each chapter is tagged with one of the following status indicators:
- Still Valid — read deeply, content remains directly applicable
- Partially Outdated — read for concepts, but implementation details may have changed
- Obsolete — skim or skip; superseded by newer standards
§Part I — Foundations of Network Performance
| Chapter | Status | Why |
|---|---|---|
| 1. Primer on Latency and Bandwidth | Still Valid | Physics of propagation delay, transmission time, and throughput are universal. Essential conceptual foundation for understanding network performance. |
| 2. Building Blocks of TCP | Still Valid | TCP's mechanics (handshakes, flow/congestion control, retransmission) still underpin nearly all transports, including QUIC. Concepts like CWND, RTT, and slow start are timeless. |
| 3. Building Blocks of UDP | Still Valid | UDP fundamentals haven't changed; modern protocols like HTTP/3 and QUIC build on top of UDP. |
| 4. Transport Layer Security (TLS) | Partially Outdated | TLS 1.3 simplified and shortened handshakes; cipher suites differ. But the lessons about latency, CPU cost, and session reuse remain true. Read conceptually, skip cipher details. |
§Part II — Wireless and Mobile Networks
| Chapter | Status | Why |
|---|---|---|
| 5. Wi-Fi | Mostly Valid | 802.11ac/ax (Wi-Fi 5/6) have higher throughput, but physics (attenuation, contention, retransmits) unchanged. Concepts of variability and buffering still apply. |
| 6. Mobile Networks (3G/4G) | Partially Outdated | 5G replaces many details, but the underlying latency hierarchy and scheduling constraints remain similar. Useful as an example of high-variance latency networks. |
| 7. Optimizing for Mobile Networks | Partially Outdated | Core strategies (compression, caching, connection reuse) still apply, but specific HTTP/1.1 optimizations are obsolete. Focus on the reasoning, not the specific techniques. |
§Part III — Protocols and APIs
| Chapter | Status | Why |
|---|---|---|
| 8. Performance of HTTP 1.x | Conceptually useful, technically outdated | Demonstrates the cost of serial connections and head-of-line blocking — the problems that motivated HTTP/2 and HTTP/3. Read to understand why newer protocols were developed. |
| 9. HTTP 2.0 | Partially outdated | HTTP/2 is still widely deployed, but HTTP/3 (QUIC) represents the next evolution. Read to learn multiplexing, prioritization, and HPACK concepts; skip older SPDY references. |
| 10. WebSocket | Still Valid | WebSockets remain a standard and behave as described. Excellent for understanding long-lived full-duplex connections. |
| 11. Server-Sent Events (SSE) | Still Valid | API and performance patterns unchanged. Still a simple, effective protocol for server-push scenarios. |
| 12. WebRTC | Mostly valid but evolving | WebRTC fundamentals remain the same, though WebTransport provides new QUIC-based alternatives. Core concepts of latency optimization and NAT-traversal still highly relevant. |
| 13. DataChannel / SCTP | Partially outdated | DataChannel implementation has evolved, but still valuable for understanding multiplexed, reliable streams in real-time applications. |
| 14. WebRTC Media Delivery | Partially outdated | Core concepts (jitter buffers, adaptive bitrate, pacing, bandwidth estimation) remain fundamental, though specific codecs and transport layers have evolved. |
| 15. APIs for Networking (XHR, Fetch) | Partially outdated | The Fetch API has modernized these patterns, and service workers add new capabilities. Core model of asynchronous, promise-based networking remains unchanged. |
§Part IV — Optimizing Application Delivery
| Chapter | Status | Why |
|---|---|---|
| 16. Primer on Optimizing Network Performance | Still Valid | Fundamental advice about measuring latency, batching requests, caching, and compression remains universally applicable. |
| 17. Measuring Performance | Still Valid | Core methodologies (RUM, synthetic testing, TCP timing, latency histograms) remain essential for web performance optimization. |
| 18. HTTP Caching and Content Delivery Networks | Still Valid | CDN architecture, caching strategies, and edge computing patterns remain fundamental to delivering high-performance web applications. |
| 19. Connection Management and Reuse | Partially outdated | HTTP/3 changes connection handling, but the underlying resource-latency trade-offs remain timeless. |
| 20. Summary and Best Practices | Still Valid | The synthesis of latency, bandwidth, and optimization trade-offs provides evergreen guidance for web performance. |
§Summary Table
| Category | Chapters | Read? | Comments |
|---|---|---|---|
| Evergreen fundamentals | 1–3, 16–18, 20 | Deeply | Universal principles of network performance and optimization. |
| Partially outdated (protocols evolved) | 4–9, 12–15, 19 | Conceptually | Focus on reasoning and principles; skip specific implementation details. |
| Mostly historical | 6, 8, 13 | Skim | Useful background for context, less practical for current work. |
| Still current APIs | 10–11 | Fully | WebSocket and SSE patterns unchanged. |
§How to Read It in 2025
Read Part I slowly. That's the transferable knowledge: latency, congestion, throughput, TCP/UDP behavior.
Skim the protocol chapters. Focus on why newer ones appeared.
Use Part IV as your systems-performance mindset guide.
Afterwards, patch in the modern replacements:
- HTTP/3 / QUIC → Cloudflare Learning Center or RFC 9000 summary
- BBR congestion control → Google's paper (2016)
- 5G / Wi-Fi 6 updates → network-engineering blogs
§TL;DR
About two-thirds of HPBN remains directly relevant in 2025. Treat the rest as historical context that explains why modern protocols were developed. The timeless parts — latency, bandwidth, queuing, congestion control — are fundamental principles that apply to any network performance work, from optimizing web applications to understanding modern protocols like HTTP/3 and QUIC.