NetworkingSystemsEngineering
Computer Networks — What Every Software Engineer Should Know
As an R&D Engineer working with networking systems, here are the core networking concepts I use every day and think every engineer should understand.
February 10, 20251 min read
Why Networks Matter for Software Engineers
Most software runs over a network. Whether you're building a web API, a real-time chat app, or embedded firmware — understanding networks makes you a significantly better engineer.
The OSI Model in Plain English
The OSI model has 7 layers. Here's what actually matters in practice:
| Layer | Name | Real-world example |
|---|---|---|
| 7 | Application | HTTP, DNS, FTP |
| 4 | Transport | TCP (reliable), UDP (fast) |
| 3 | Network | IP addresses, routing |
| 2 | Data Link | MAC addresses, Ethernet |
| 1 | Physical | Cables, WiFi signals |
TCP vs UDP — When to Use Which
# TCP — reliable, ordered, slower
# Use for: web requests, file transfers, email
import socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # SOCK_STREAM = TCP
# UDP — unreliable, unordered, faster
# Use for: video streaming, gaming, DNS lookups
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) # SOCK_DGRAM = UDP
Key Takeaway
You don't need to memorize every RFC. But understanding IP addressing, TCP handshakes, and DNS resolution will help you debug production issues 10x faster.