network note

network.md

Open Systems Interconnection model (OSI model)

• https://en.wikipedia.org/wiki/OSI_model

All People Seem To Need Data Processing

1. Physical Layer
   • Bit, Symbol
2. Data Link Layer
   • Frame
3. Network Layer
   • Packet
   • addressing, routing and traffic control
4. Transport Layer
   • Segment, Datagram
   • segmentaion, acknowledgement and multiplexing
5. Session Layer
   • Data
   • managing communication session
6. Presentation Layer
   • Data
   • translation: character encoding, data compression and encryption/decryption
7. Application Layer
   • Data
   • API

Load Balancing

• https://www.nginx.com/resources/glossary/layer-7-load-balancing/

• https://www.nginx.com/resources/glossary/layer-4-load-balancing/

• Layer 4

  • forward network packets to and from the upstream server
  • Network Address Translation (NAT)
  • limited routing by inspecting the first few packtes in the TCP stream (address)

• Layer 7

  • based on the content of the message (URL, header, cookie, etc.)
  • apply optimizations and changes to the content (compression and encryption)