Top-down ch1 Review of computer Network

The words written in the front:

The title of the first chapter is computer network and Internet. It mainly explains some basic concepts.

1.1 what is the Internet

(1) specific composition: hosts, communication links, packet switches. Hosts is the edge of the whole Internet, and switches is core. Host includes clients, servers and so on. Packet swithces is made up of routers and switches.

(2) communicate with each other:

Protocol: a standard for communication between different network devices.

1.2 Network Edge (end system)

(1) access network: the end system is connected to the first router on another path.

Ethernet: devices are connected to the switch before being connected to the router.

WIFI:

1.3 packet switching and circuit switching

The Internet uses packet switching. The advantage of packet switching is that it can share resources, but cannot support real-time services.

The telephone network uses circuit switching.

1.4 delay, packet loss and Throughput in packet switched Networks

1.5 Seven-layer model and corresponding protocols

1.6 facing the network of *

(1) * PC

(2) * * server, DOS (Denial of Service).

(3) sniffing grouping. Not yet.