Notes/UNB/Year 4/Semester 2/CS3873/2024-01-26.md

1.3 KiB

Lecture Topic: Web Protocols

Encapsulation/Decapsulation

Each layer of a network adds a header, that encapsulates the rest of the data When a packet is decapsulated, each layer strips away its header after it is done processing

Network Applications

Applications are distributed since they involve multiple end systems that exchange dat which each other

Application Architectures

Dictates how applications interact on a network

  • Client/Server architecture
    • Server: An always on host which services requests from many other hosts
      • Data is often stored on the server
      • Data centers can be used to create powerful virtual servers
    • Clients: Connect through to the server
  • Peer to peer architecture
    • No always on server
    • Arbitrary end systems directly communicate
    • Peers request service from other peers and provide service in return to other peers
      • Self scalability: New peers bring new service capacity as well as new service demands
    • Peers are intermittently connected and change IP addresses (complex management)
    • Examples include BitTorrent (P2P file sharing)

Basics of Web and HTTP

Invented by Tim Burners-Lee Client Server model

  • Client is a web browser that requests and receives, and then displays web objects
  • Server is a web server that sends objects in response to

HTTP Request

Diagram in slides