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Computer Networks
Book page on Pearson.
Computer Networks
Authors: Andrew S. Tanenbaum, David J. Wetherall
Publisher: Pearson, 2021 (6th Edition)
Length: ~960 pages
Network models, protocols, routing, reliability, security and wireless networks.
OriginalKey topics
Models and protocols
OSI/TCP/IP, encapsulation, addressing and roles of each layer.
Routing
BGP/OSPF at the level of ideas, metrics, paths and route resiliency.
Transmission reliability
Losses, retrays, windows, congestion control and QoS.
Network Applications
HTTP/HTTPS, DNS, email, RPC and network application patterns.
Safety
TLS, certificates, authentication, basic threats and protections.
Wireless networks
Wi‑Fi, LTE/5G, environmental impact on stability and latency.
Network stack and request path
The book views the request chain as moving through levels. This helps you quickly find where delays and losses occur.
Application
HTTP, DNS, gRPC, WebSocket, data formats and semantics.
Transport
TCP/UDP/QUIC, congestion control, reliability and ordering.
Network
IP, addressing, routing, NAT, MTU and fragmentation.
Link / Physical
Ethernet, Wi‑Fi, mobile networks, signal and losses.
Latency budget
Metrics that are important to keep in mind
How the book is organized
Part 1
Physics and link level
Signals, coding, error detection, and basic LAN protocols.
Part 2
Network & Transport
IP, routing, TCP/UDP/QUIC, congestion control and reliability.
Part 3
Application protocols
DNS, HTTP, email and network application architectures.
Part 4
Security & Wireless
TLS, threats, cryptography, and Wi‑Fi and mobile networks.
What is really useful in an interview?
- Estimating RTT and understanding how the network affects the latency budget.
- TCP/UDP/QUIC differences and their impact on service architecture.
- Routing and the influence of geography on accessibility.
- Security: when TLS is needed, where the transport ends and the application begins.
Why is it important for System Design
- Understanding network delays and protocols helps evaluate latency.
- Knowledge of routing is useful for architectures with global traffic.
- Network failures and their models are critical to the reliability of distributed systems.
- The protocols define how to design retries, timeouts, and load balancing.
Who is it suitable for?
Backend engineers, SREs and anyone who designs network services, protocols and high-traffic systems.