计算机网络与因特网论文英文版.docx

1、计算机网络与因特网论文英文版MENU1、LAN technology 41.1 LAN Overview 41.1.1 Emergence and development of local area network 41.1.2 LAN Features 41.1.3 LAN components 51.1.4 LAN Architecture and IEEE802 standard 51.1.5 Media access control methods 61.2 Ethernet 71.2.1 the technical characteristics of the Ethernet 81

2、.2.2 IEEE802.3 Ethernet architecture 81.2.3 10Mbps Ethernet 81.3 Fast Ethernet 101.3.1 IEEE802.3u Fast Ethernet 101.3.2 100VG-AnylAN 111.4 Fiber Distributed Data Interface FDDI 111.4.1 FDDI dual ring structure 111.5 Switched Ethernet 111.5.1 A problem shared network 111.5.2 The characteristics of a

3、switched network 121.5.3 Ethernet Switches 121.5.4 The working principle of switched Ethernet 121.5.5 VLAN 131.6 Switched Ethernet Application 151.6.1, the characteristics of Gigabit Ethernet 151.6.2 IEEE802.z Gigabit Ethernet standard 151.6.3 IEEE802.ab Gigabit Ethernet standard 161.7 Gigabit Ether

4、net 161.7.1the technical characteristics of Gigabit Ethernet 161.8 Asynchronous Transfer Mode 171.8.1 ATM features 171.8.2 The basic skills of ATM 181.8.3 ATM interface standard 181.8.4 ATM architecture 181.9 Wireless LAN 191.9.1 Wireless LAN Overview 192、WAN 202.1 Overview Overview of network inter

5、connection network interconnection 202.1.1 Applications of computer network interconnection 202.1.2 Interconnection model 212.1.3 Several forms of network interconnection 212.1.4 Basic requirements for network interconnection 212.2 Network interconnection devices 222.2.1 Repeater 222.2.2 Network bri

6、dge 222.2.3 Router 242.2.4 Gateway 252.3 Routing algorithm and routing protocol 262.3.1 Static and dynamic routing 262.3.2 Routing algorithm 262.3.3 Routing Protocol 272. 4 WAN technology 292.4.1 the wide area network reference model 302.5 Interconnection agreements TCP / IP 302.5.1 TCP / IP protoco

7、l suite 312.5.2 IP network interconnection agreement 32IP data packet must be submitted to the data link layer, framing package can be sent before. As supported by different networks with different maximum frame length (128-4470 bytes), generally less than IP packet, it is usually the largest IP dat

8、a packets into smaller packets, and then send the packet (both above) . Packet decomposition of the larger, higher communication efficiency. Recombination is the reverse process of sub-section, it is the number of IP segments reassembled into the original IP packet. 2.6 Internet Address 332.6.1 Repr

9、esentation and classification of IP addresses 342.6.2 Subnet mask 342.6.3 Specific IP address 352.6.4 Address Resolution Protocol and Reverse Address Resolution Protocol 362.6.5 Control Message Protocol ICMP 362.6.6 UDP protocol 362.6.7 TCP protocol 373 Application 383.1 Background 383.2 Design requ

10、irements 383.3 Planning and Design 393.3.1 The design of network topology 393.3.2 The general structure of the network 403.3.3 LAN bandwidth requirements 413.3.4 Cabling design principles 413.3.5 Central Office Planning and Design 423.3.6 Selection of network equipment 433.4 Detailed design 443.4.1

11、Flow Calculation 443.4.2 Detailed Configuration 453.4.3 IP address distribution 463.5 References 47ABSTRCTTitle Computer Network and Internet AbstractAs rapid development of computer network technology today, the use of information transmission network has become an essential way to run. With the of

12、fice information and automation needs of various units to improve office efficiency, and promote information exchange, meet the requirements of modern office needs to set up business office LAN. Formation of all aspects involved in the enterprise LAN are many, first of all need a proper design and p

13、lanning, then need to deal with wiring, network equipment selection and configuration, server equipment selection and configuration, network software installation, etc., which require each implementation step by step and, finally, the need for normal daily maintenance, this paper, LAN, WAN and LAN d

14、esign Enterprise Brief Introduction.Keywords: LAN WAN Network Layout Switch1、LAN technology1.1 LAN Overview1.1.1 Emergence and development of local area networkLAN(Local Area Network, LAN) is a computer network, LAN is in a smaller range (an office, a building, a public works, etc.), the use of comm

15、unication lines to a number of computers (usually computer) and connecting peripherals, data communication and resource sharing . LAN research began in the 20th century, 70s, 80s is the decade of the great development of local area network, LAN technology is the occurrence of 90 years of change. Eth

16、ernet is a typical representative.Now, in the world every day, thousands of local area network running, and their number far exceeds the WAN. LAN bandwidth from the 10M, 100M, 1000M, 10G, 1Tbps.1.1.2 LAN Features1.1.2.1 The three properties of the LAN1) LAN is a communications network, he only commu

17、nications. It includes only the lowest two layers of OSI reference model function, so connected to the LAN data communications equipment must be added to high-level protocol and network software can be composed of computer network.2) LAN connection object is the data communications equipment, includ

18、ing computers, terminals, etc.3) LAN coverage is small, the transmission distance limited. 1.1.2.2 LAN features1) LAN is a communications network.2) LAN connection object is the data communications equipment, including computers, terminal equipment.3) small local area network coverage.4) high transm

19、ission speed, 1Mbps 10Gbps.5) The propagation delay is small, a few milliseconds and tens of milliseconds.6) low bit error rate, 10-8.7) attributable to a single organization and management.1.1.3 LAN componentsLAN is Consists of hardware and software systems.1.1.3.1 Hardware systemHardware system is

20、 include of network servers, workstations, network interface cards, network devices, transmission media and connecting parts, and various adapters.1.1.3.2 Network SoftwareNetwork System Software (core): including network operating systems, network protocols and network communication software.Web app

21、lications: management information systems, remote education, digital libraries, etc.1.1.4 LAN Architecture and IEEE802 standardshown. System follows the IEEE 802 LAN standard ISO / OSI reference model, with a main address - the lowest two levels of physicalLayer, data link layer functions and the in

22、terface with the network layer service, high-level functions related to Internet interconnection. Data link layer is divided into two sub-layers: Logical Link Control LLC and media access control MAC (Medium Access Control) (or: media access control).1) Physical LayerAchieve bit-stream transmission

23、and reception, creation and deletion synchronization sequence to provide the signal used, coding, and medium, provided the network topology and transmission rate.In the local area network, the signal coding is often used Manchester encoding, media are twisted pair, coaxial cable, optical fiber, mult

24、i-topology as bus, star, tree, ring; transfer rate of 1Mbps, 4 Mbps, 10 Mbps, 100 Mbps and so on.The physical layer LAN standards developed by the main content:1. Transmission medium and the corresponding distance2. Transfer rate3. Physical interface mechanical properties, electrical properties, per

25、formance characteristics and normative characteristics4. Transmit coded signals5. Error checking and synchronization signal generation and deletion6. Topology7. Physical Signaling: service primitive2) MAC sub-layer:MAC sub-layer (MAC sublayer) main function is a reasonable allocation of the channel

26、to address the problem of channel competition and send data, the data received will be assembled on the floor with the MAC address into the fields and error detection data frame, the receiver data and complete the demolition of the frame address recognition and error control.IEEE 802 standard specif

27、ies the MAC address of 48 bits, 16 hex numbers by 12, each card has a globally unique MAC address. Manufacturers producing cards to apply to the IEEE MAC address of the first three bytes (high 24), known as the address block, after the three bytes discretionary by the manufacturer, the production ne

28、twork cards MAC 6 bytes address is hardcoded in the network card.3) LLC sub-layer (Logical Link Control sub-layer):Main function is to establish, maintain, sustain and release of data link, providing one or more service access points to the high-level (network layer) to provide connection-oriented a

29、nd connectionless services, In addition, to ensure error-free transmission through the LAN, LLC layer also provides error control and flow control functions, it has nothing to do with the transmission medium.1.1.5 Media access control methods1.1.5.1. Carrier Sense Multiple Access / Collision Detecti

30、on (CSMA / CD)In the shared channel network, each site can determine the state of the channel. Judgement is to use the site to a receiver on from the channel receiver channel signal, and if the channel level has changed, that is, the so-called carrier, indicating that the channel by other sites occu

31、pied; if the channel level has not changed, indicating that the channel is idle.CSMA control scheme:(1) a station to be sent, first of all need to monitor the bus to determine whether there is media to send signals to other sites.(2) If the medium is idle, you can send.(3) If the medium is busy, the

32、n wait a certain interval and try again.The maximum utilization of the media depends on the length and propagation time frame. Frame longer or shorter travel time, higher utilization by the media.CD collision detection: Send data, send the side edge detection, but the conflict is detected the signal, then cancel the transfer, send a short jamming signal, to strengthen the conflict, so that all sites tha