Networking

OSI Model

• Application Layer 7 - network apps, user interface
• Transport Layer 4 - end-to-end connections, reliability, flow control
• Network Layer 3 - logical address, routing

Layer 3, IP

• IPv4, 4 bytes
• IPv8, 16 bytes
• mask, first x bits

Layer 4, TCP, UDP

• TCP - throughput, latency
• UDP - real-time. lossy

• 3-way handshake - SYN, SYN-ACK, ACK
• connection termination (4-way handshake)

Layer 7

• REST
• GraphQL