This book can be easily considered one of the pillars of optimization.
It is really incredible how the author begins the journey from the lowest OSI layer to the browser and the newest trends in realtime communication.
The book starts with detailing each different medium (fiber, satellite , radio , wifi) we can nowadays use in order to send packets over the network.Interestingly enough he gets you into data transmission , signal processing , electronics and physics in order to give you an idea on how each medium impacts your app's performance and their hidden latencies.
The book then shifts to TCP and UDP, TLS, TURN , ICE and STUN protocols.Awesome chapter , i would have never known the intricacies of TCP and its adaptability regarding the unreliability of the underlying network.(The congestion window mechanisms part was insane).
Another chapter is dedicated to wireless networks.
The most interesting part was the one regarding mobile networks.
The author does a terrific job by first explaining how your handset works , how it efficiently uses its battery in order to accomodate the ever consuming radio(s) (2G,3G,4G) , its complicated RRC (radio resource controller) protocol that manages the exchanges with the radio tower and handles your phone state-machine that manages your battery and its sensible connection with its radio.
Then he goes overdrive detailing LTE radio networks , with their architecture and components (RAN, ETC-SGW,PGW,MME) , the way they manage to serve users that are in constant motion (MME) switching them from radio tower to radio tower , updating their position in realtime and performing billing and security checks ; the way they direct packets from the public internet to their gateways ,parse , corect them , resolve users , find corresponding tower and negotiate protocols with the user handset to in the end forward the message.
Its really interesting that the principles of clustering and load balacing that apply nowadays to any web application component (database, api , web app) were present in the telecom domain for a very long time and more importantly , not only for software but for radio towers as well.
The book then moves to HTTP , HTTPS , XHR(interesting history part here ) , SSE , Websockets and last but not least WebRTC.
Even though the last part was detailed and interesting i found it nowhere close to the one regarding mobile networks( could be due to the fact that i was already familiar with the concepts)
Awesome read and i recommend it wholeheartedly for anyone interested in building high performance applications.It is one of those reads which takes a hollistic view on all the layers and components involved to give you a neat idea on how to build something !