High Performance Browser Networking
Do you like fast websites? No? Never mind then. Oh, you… you at the back… you like fast sites? Well, this is certainly a resource you’re going to want to bookmark. This book is from Ilya Grigorik which is available to read for free on the web.

Performance is a feature. This book provides a hands-on overview of what every web developer needs to know about the various types of networks (WiFi, 3G/4G), transport protocols (UDP, TCP, and TLS), application protocols (HTTP/1.1, HTTP/2), and APIs available in the browser (XHR, WebSocket, WebRTC, and more) to deliver the best—fast, reliable, and resilient—user experience.
An excerpt from High Performance Browser Networking