Network Overview __ Network

1, Network Division

Local Area network: Small coverage, closed
wide area network: distance, need to rent bandwidth
Internet ISP: Self-built room, provide internet access Service

2. Computer Data communication Process

Include IP address: Packet
contains MAC address: Data frame

3. OSI Reference Model 3.1 Layered Model

Application Layer: The program presentation layer for network communication
: processing transmission encryption, compression processing (Web page encoding UTF-8)
Session Layer: Multiple pages open, use to session
Transport layer: reliable/unreliable transmission, flow control
Network layer: Responsible for selecting the best path, Planning IP Address
Data Link layer: The Beginning and end of the frame processing, transparent transmission, error checking (FCS)
Physical Layer: interface standards, such as network cable, high-low voltage to 0, 1 mapping relationship, speed up

3.2 Tiered Advantage

· IPV6 switch to IPV4, only need to modify the network layer
• Multiple networks to build, you can use a number of IP addresses at the network layer to the network-
error guidance,
· Physical layer Failure--View computer connection status, send packet and receive packet is equal
· Data link Layer fault--MAC address conflict, campus network owes fee ·
Network layer fault--IP address, subnet mask, gateway, router parameter configuration error
· Application-Layer Failure-firewall

3.3 Data Encapsulation

Continued 3.4 Network performance Parameters

Continued