1. Network Applications
- Read and write data over network
- Dominant model: bidirectional, reliable byte stream connection
- One side reads what the other writes
- Operates in both directions
- Reliable (unless connection breaks)
Blow we will introduce three examples: the world wide web, BitTorrent and Skype
- the world wide web: A client-server model. A client opens a connection to a server and requests documents. The server responds with the documents.
- BitTorrent: A peer-to-peer model. Swarms of clients open connections to each other to exchange pieces of data, creating a dense network of connections.
- Skype: A mix of the two models. When Skype clients can communicate directly, they do so in a peer-to-peer fashion. But sometimes the clients can’t open connections directly, and so instead go through rendezvous or relay servers.