History of the Internet
In 1969, the U.S. Department of Defense's Advanced Research Project Agency
(Advanced Research Project Agency, or ARPA) carried out offsite computer interconnections, which resulted in the precursor to the Internet - the ARPAnet
In 1977-1979, ARPAnet introduced the TCP/IP architecture and protocol in its current form.
In 1986, the National Science Foundation (NSF), using the TCP/IP protocol will be distributed throughout the United States of America's six supercomputer centers for scientific research and education services interconnection, and support for regional networks, the formation of the NSFnet, replacing the ARPAnet as the Internet's backbone network.
In 1989, it was renamed Internet and opened to the public
In 1994, the Internet in the United States was fully taken over by commercial organizations
History of the Internet in China
The first phase (1989-early 1994) --- indirect connection to the Internet with E-mail as the main application
The second phase (1992-early 1994)
The first phase (1992-early 1994)
was the first phase (1992-early 1994)
of the Internet.The second phase (1992-1994.4) full-featured direct connection with the International Internet, i.e., the opening of the International Internet
The third phase (1994.4-now) --- In April 1994, China joined the Internet for the first time, and the construction of the Interent was comprehensively rolled out.
See: A Review of China's Internet Development
c.ac.cn/gb/news/news_special/5_years/ztyj/ppt/ybp1/tsld001.htm
Chinese Internet Network Information Center (CNNIC) www.cnnic.net.cn is in charge of the Domestic IP address and domain name application registration
China's four major Internet networks were formed in 1996
CERNET China Education and Research Network
China Education and Research Computer Network (CERNET) at www.edu.cn
CSTNET China Science and Technology Network (CSTNET)
CSTNET China Science and Technology Network (CSTNET) at www. cstnet.net.cn www.cnc.ac.cn
ChinaGBN China Golden Bridge Network National Public Economic Information and Communication Network
China Golden Bridge Information Network URL: www.gb.com.cn
ChinaNet China Public Internet Provides the public with international networking services for computers
< p>China Telecom Web site: www.chinatelecom.com.cnOther Internet units
Also:
China Unicom Internet (UNINET ) www.chinaunicom.com.cn
China Netcom Public Internet (CNCNET ) www. cnc.net.cn
China Mobile Internet (CMNET) www.chinamobile.com
China International Economic and Trade Internet (CIETNET) www.ciet.net
China Great Wall Internet (CGWNET) www.cgw.net.cn
< p>China Satellite Group Internet (CSNET) www.chinasat.com.cnInternational Export Bandwidth
The total amount of China's international export bandwidth is 18,599 M. The connected countries are the United States, Canada, Australia, Britain, Germany, France, Japan, Korea and so on. The distribution is as follows (2003-7)
China Science and Technology Network (CSTNET): 55M
China Public Computer Internet (CHINANET): 10959M
China Educational and Scientific Research Computer Network (CERNET): 324M
China Unicom Internet (UNINET): 1435M
China Netcom Public Internet (Netcom Holdings) (CNCNET): 2112M
Broadband China CHINA169 Network (Netcom Group): 3465M
Chinese International Economic and Trade Internet (CIETNET): 2M
China Mobile Internet (CMNET): 247M
China's Great Wall Internet (GWI): 324M
China's Great Wall Internet (GWI). /p>
China Great Wall Internet (CGWNET): (under construction)
China Satellite Group Internet (CSNET): (under construction)
On January 15, 2004, CNNIC released the thirteenth statistical report on the development status of China's Internet network, with new developments nic.cn/html/Dir/2004/01/15/ 2080.htm
By December 31, 2003, the total capacity of China's international export bandwidth was 27,216M
Internet Definition
Internet is a worldwide computer system consisting of a variety of different types and sizes of independently operated and managed computer networks. The Chinese name is "international interconnection network", "Internet", "inter-network" and so on. All people can enjoy and use all kinds of information on the Internet through the network connection.
TCP/IP-based InterNetwork
ISP (Internet Service Privider)
ICP (Internet Content Privider)
Basic working principle of Internet
Packet switching
Packet switching
Packet switching
Packet switching
Packet switching
Equal access to **** resources is guaranteed to all computers by utilizing the fact that each computer can only transmit a certain amount of data at a time
Internet Protocol IP
Transmission Control Protocol TCP
Client-server (C/S)
Client sends out a request for a database or information, which is accepted by the server program in the host computer. The server program in the host computer accepts this request and answers it in a specific format, which is then recognized by the client program and displayed to the user.
Client/Server is built on a LAN.
Browser and Server (B/S structure)
The user interface is realized entirely through the ever-maturing WWW browser technology, combined with the browser's multiple Script languages (VBScript, JavaScript...) and ActiveX technology, which originally required complex specialized software to realize the powerful functions, and saves development costs.
Browser/Server is built on a wide area network.
Internet changes the world
Information acquisition and distribution
Online communication
E-commerce
Internet phone, fax
Internet office
Distance education, telemedicine, online games, etc.
The number of people on the Internet: 59.1 million (Male:59.3% Female:40.7%)
Statistical Chart of the Number of Internet Users in China
Basic Functions of the Internet
There are 3 basic functions of the Internet: e-mail, remote login, file transfer.
Email: the most widely used on the internet, is the most important and basic application of the internet, can transmit text, images, sound and other media information, can send the information to multiple recipients at the same time, but also can be forwarded to a third party, he is slower than the real-time fax, but the cost is cheap.
Remote login: the user through the telnet command, so that their computer temporarily become the terminal of the remote computer, directly call the remote computer on the resources open to the public, you can query the database, retrieve information, or the use of remote computers to complete the work that can only be done by giant computers, the internet on the Internet, many of the services are accessed through the telnet to achieve.
File transfer: FTP (File transfer protocol) users to transfer files between two networked computers, free access to the rich resources on the Internet.
In addition to the above basic services, but also has:
Newsgroups (usenet news): open discussion of network topics
Electronic bulletin boards BBS: posting information or put forward the view
Internet Chat MSN, ICQ :online transmission of information, conversation, sending files and voice
Query service ( Finger)
Wold Wide Web
IP address
IP (Internet Protocol) address, i.e., an address expressed in the language of the Internet Protocol
A 32-bit binary number divided into four segments, with dots separating the segments and eight bits in each segment, which can be represented by a decimal number less than 256.
IP address contains two parts: one is the network address, the other is the host address
In order to adapt to the requirements of different network sizes, IP address is mainly divided into three classes A, B, C, in addition to class D (multi-access broadcast address), class E (experimental address)
such as the university's Web site address: 210.35. 74.2
IP address
IP address space
First byte Number of network addresses Number of network hosts Total number of hosts
Class A network 0-127 128 2(8-1) 16777214 224-2 2147483392
Class B network 128 -191 16384 2(16-2) 65534 216-2 1073709056
Class C Networks 192-223 2097152 2(24-3) 254 28-2 532676608
Total 2113664 16843002 3753869056
Class A: 0.0.0.0~127.255.255.255 Segment 1 is the network address, large network
Class B: 128.0.0.0~191.255.255.255 Segments 1,2 is the network address, medium network
Class C: 192.0. 0.0.0~223.255.255.255 Segments 1,2,3 are network addresses, small networks
Class D 224 ~ 239 Class D is reserved as a broadcast address for multipoint transmissions
Class E 240 ~ 254 Class E is an experimental address
In a Class A address, 127.x.y.z is reserved for loopback testing.
All 1's in each byte (8 bits) are not assigned (i.e., cannot be 255), and all 0's in the first byte indicate a local network address
Those IP addresses are internal
The following ranges of IP addresses are LAN (intranet) addresses:
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
169.254.0.0 - 169.254.255.255
192.168.0.0 - 192.168.255.255
Computers on the local area network (LAN) can access computers on the Internet, but computers on the Internet cannot access computers on the Internet. computers on the Internet cannot directly access computers on the LAN.
Dynamic, Static IP Addresses
Dynamic Host Configuration Protocol (DHCP) The automatic assignment of IP addresses on a network.
Dynamic IP address: multiple users share several IP addresses, each time a user dials into the network, through the DHCP from the ISP to dynamically get the IP address dynamically assigned an IP address.
The assigned ip address is always changing (today's ip address is different from yesterday's ip address, and this ip address is different from 2 hours ago), then it is a dynamic ip address.
Static IP addresses: ISPs set up special IP addresses for certain users, and the assigned IP address always stays the same (the ip address is the same every day), so it is a fixed static IP address.
Note:
The computers in the LAN are not the same as the external computers although the ip address is also unchanged, they can't get the static ip address by applying to the telecommunication service organizations such as CNNIC, ISP, etc.
Establishing the static ip address is the best way to get the static ip address.
Preliminary preparations for the establishment of a website
Home or office station
Telephone line, ISDN, ADSL, CABLE MODEN, the use of dynamic ip Internet access for home users, you can through PeanutHull2.0, DNS2GO, mountain outside the mountain and other software, register dynamic domain names.
Internet access is the same as above, but through the LAN, campus online network users (internal Web site) , through the Web Shanwai Tong, to register dynamic domain names.
Refer to the download URL
.com/soft/6352.html
210.35.74.2
The domain name of the WWW server of the Campus Network Center of the Institute of Foreign Trade (IFT)
Look up the domain name addresses of the websites of Shanghai Jiaotong University, Fudan University, and 263
Look up the IP address corresponding to the domain name ( using the ping command)
Domain name structure
Top-level domain name-organizational domain
Type of organization or institution denoted by the domain name
com Commercial institution
edu Educational institution or facility
gov Non-military government institution
int International institution
mil Military institution or facility
net Network organization or institution
org Non-profit organization or institution
Top-level domains - geographic domains
Domain name Indicates a country or region
cn The People's Republic of China*** and the People's Republic of China
hk Hong Kong, China
mo Macao, China
tw Taiwan, China
sg Singapore
uk United Kingdom
fr France
jp Japan
China's second-level domain name system - category domains
Second-level domains Indicates a category
ac Scientific research institutes and technology management
com Industrial, commercial and financial enterprises
edu Educational units
gov National government departments
net Internet, access network information and operation centers
org Various social groups and civil non-profit organizations
China's second-level domain name system - administrative regions
Chinese second-level domain names Administrative Regions
Second Level Domain Names Administrative Regions
bj Beijing
sh Shanghai
tj Tianjin
cq Chongqing
js Jiangsu
zj Zhejiang
gd Guangdong
sn Shaanxi
Domain name examples
Please analyze the following Domain name belongs to the industry, country (region):
World Wide Web/Globe WWW
Information network formed on the Internet on the basis of hypertext
Internet a large library, Web nodes like a book in the library, Web page is a page in the book
HomePage (HomePage) is the HomePage is the starting point of a Web node, like the cover or table of contents of a book
URL (Universal Resource Locator)
Uniform Resource Locator: the unique address of each Web page
/chn/yxsz/index.htm
, and then into the "Educational Resources" web page ......
Collect the URLs of the Ministry of Education, Sina, and CCTV in "News"
After the above three operations are completed, the Snagit is used to intercept the favorites (as in Example 2), saved as c:\test\favorites screenshot.jpg
With the assignment 2
Search operations
How many floors were there at the time of the construction of the Big Wild Goose Pagoda, a famous monument located in Xi'an?
A.seven floors B.three floors C.five floors D.six floors
China's earliest census figures are about:
A.4,360,000 B.13,550,000 C.59,580,000 D.40,000,000
Li Lin saw an indicator (WBC) that was on the high side of his routine blood test report card.
A. Platelet count B. White blood cell count C. Red blood cell count D. Hemoglobin
There is a missed phone number on his cell phone: 58796391, and he wants to search for which district in Shanghai the call is coming from before calling back?
A.Changning B.Huangpu C.Luwan D.Pudong
What does the word "kung pao" in the famous dish "Kung Pao Chicken" originally mean?
A. Name of the dish B. Name of the recipe C. Name of the place D. Name of the official E. Name of the person
Save the search results to c:\test\SearchExercise.txt, where you only need to fill in the question number and the selected answer.
Packing the assignment
Check the c:\test folder to see if there are:
One htm web page file and a corresponding subfolder
Two jpg image files
Two txt text files
Take your machine number (two digits) + name + IE Assignment.rar as the file name to compress (package) the above content as The above content is compressed (packed) and used as an attachment for sending emails.
Here's how to send emails
Two
Email account settings before enabling OE
Your E_mail address
0101001@shift.edu.cn
Account name (username): your student number
Secret code: the last five digits of your ID card number (the last digit may be x or x)
Account name: your student number
Secret code: the last five digits of your ID card number (the last digit may be x or x) (may be x or X )
Capacity: 2M
Tools→Account→Mail→Add→Mail→
(If there is another student's account, please make sure to delete it first)
Display name (sender's name) →fill in your name
Email address (reply address) →fill in your real E-mail address
POP3 Incoming mail server: our university's incoming mail server address mail.shift.edu.cn
SMTP Outgoing mail server: our university's outgoing mail server address mail.shift.edu.cn
Account name→fill in your account name
Password→fill in your password
Remember your password→ Select the checkbox
Tools→Accounts→Mail→Select the current account→Properties→Server
Select the checkbox in front of "My server requires authentication"
Within the class
File→New→Mail→(or create a message)
Recipients→
老师邮箱的用户名@shift.edu.cn
Subject → Machine number (two digits) + Name + IE Assignment
Body of email → A random sentence or suggestion for this course
Finish with your number, name, and class
Mail can have a background (e.g., Sunny in the Create Mail dropdown, etc.) <
Split line (Insert→Horizontal line)
Attachment→Select your packed assignment file in the c:\test folder
e.g. 01 Zhang IE Assignment.rar
Click Send
Check the Outbox folder to see if the email If it exists, it has not been sent
Check the "Sent Mails" folder to see if it exists, if it exists, it has been sent
Example of composing an e-mail
Apply for a free e-mail
Apply for a free e-mail at citiz or sohu A free E-mail
Apply for free E-mail at citiz:
mail.citiz.net
or/index.jsp
Note that you should check the information about incoming mail servers (POP3) and outgoing mail servers (SMTP), etc., which are mentioned in the FAQ
Sending mail, Incoming mail servers
Outgoing mail servers
SMTP outgoing mail servers (outgoing mail post offices)
Simple Mail Transfer Protocol
Our outgoing mail server in Songjiang: mail.shift.edu.cn
Incoming mail servers
POP3 Incoming Mail Server (Incoming Post Office)
Post Office Protcol 3
The incoming mail server of our school in Songjiang: mail.shift.edu.cn
Wherever you have an account, you can pick up mail from the incoming mail server there
Commonly Used Smtp, Pop3 Servers Comparison table
Basic OE settings
Sending/receiving servers can be same or different (including off-site)
Recipient, cc, bcc
Multiple people: Separate Email addresses with a semicolon or comma
Address book and its applications (import/export)
Add attachments
Send text, pictures, sounds and other files as attachments
Handling of incoming e-mail attachments
Opening (watch out for viruses)
Saving
Tools→Options→Security→Meaning of "Do not allow attachments with viruses to be saved or opened"
What is the meaning of "Don't allow attachments with viruses to be saved or opened" in Tools→Options→Security?
View Email Properties
OE Advanced Settings
Multi-Account Settings
Keep Backups of Emails
Tools→Accounts→Mail→Check the Current Account→Properties→Advanced
Keep a Copy of Emails on the Server
Authentication
Tools→Accounts→Mail→Check the Account→Properties → Server→
My Server Requires Authentication
OE Mail Rules
Mail→Create Rule from Mail, Block Sender
Tools→ Mail Rules→ Mail→
Rule Conditions, Rule Actions, Rule Descriptions, Rule Names
What it does
Blocks Junk Mail
< p>Save in categories (create folders first)Other OE operations
Folders
Distribute incoming E-mail to different folders in conjunction with mail rules
Tools→Add sender to address book
Save E-mail
Menu: File → Save As
Clipboard (save part of the body of the message)
Print e-mail
View → Sort by, Columns, Layout
Email security
Using encryption technologies such as digital certificates, PKI, symmetric encryption algorithms, digital signatures, digital envelopes, and so on, it is possible to set up an encryption, decryption, and identity authentication system with a very high level of security and to ensure that the electronic transactions are carried out in an effective and safe manner. The system ensures that electronic transactions are carried out effectively and securely, so that the information is not known by other parties except the sender and receiver (confidentiality); the transmission process is guaranteed not to be tampered with (integrity and consistency); the sender is sure that the receiver is not a fake (authenticity and non-disguisability of the identity); and the sender cannot deny that he/she is sending the behavior (non-repudiation).
The Certification Authority (CA-Certificate Authority), as an authoritative, trustworthy, and impartial third-party organization, is specifically responsible for issuing and managing the digital certificates required by all entities involved in online transactions. It serves as an authoritative body that effectively manages keys, issues certificates to prove the validity of the keys, and associates the public key with a particular entity (consumer, merchant, bank).
Main applications: online tax filing, office, bidding, trading, mail and business administration
Digital certificates: personal or organizational identity cards on the Internet, through the use of symmetric and asymmetric cryptography and other cryptographic techniques to establish a set of strict identity authentication system .
Digital signature: the sender generates a digest based on the message and encrypts the digest with its own signature private key. The message and the digital digest encrypted with its own signing private key are combined to form a digital signature.
E-key: also known as electronic key, in fact, is a kind of with unified provisions of the encryption algorithm, can decrypt the provisions of the encrypted data, and can store the digital certificate of a kind of special hardware storage media.
Email Truck
Email Truck is a tool for accessing HTTP, FTP through an E-mail gateway server. Often if it takes you a few minutes to connect to a web page, or a file can only be downloaded at 0.2k/sec, or you simply can't access the address directly (as is often the case for 169 A/B users), E-mail Truck can take care of it all for you by e-mail. All you have to do is fill in the URL, or just "Copy to clipboard". The basic technology of Email Truck is exactly the same as Mr Cool, but it is designed to surpass Mr Cool completely. Bugs that were common in Mr Cool are gone, the monitor dialog pops up at the top, and the send queue fails without a dead loop. Batch processing, source file downloading, and more powerful monitoring settings have been added. And the interface is absolutely refreshing.
Email Express
Sometimes you may encounter a situation where you need to send an email to a friend quickly, but with regular email delivery, you can't guarantee that the email will be delivered immediately.
Foxmail provides a mail express function, which is characterized by the ability to find the server where the recipient's mailbox is located, and directly deliver the mail to the other mailbox. This way, when you finish sending, your friend can receive the mail immediately.
To use the Speedpost feature, you just need to click "Speedpost" in the "Mail" menu or the toolbar after you finish writing an email.
Note: Special Delivery can only be sent to one recipient, and only one e-mail address can be entered in the recipient field.
Additionally, the Special Delivery function needs to call the domain name server (DNS) to query the IP address of the recipient's mailbox, so you must fill in the domain name server address in the system. If you fill in the domain name server address in the ICP/IP property dialog box of Windows system, Foxmail will get and use the address automatically. Users can also go through "Options"|"System Settings" in Foxmail menu and select "Mail Express" in the pop-up dialog box to fill in the domain name server IP address. IP address. You can fill in two name servers or just the first one.
Foxmail Express Forwarding
You need to call the domain name server (DNS) to query the corresponding IP address of the recipient's post office
If you fill in the domain name server address in the TCP/IP attribute of the Windows system, Foxmail will use it automatically
Set up the menu of Foxmail: Options → System Settings→ Mail Express, fill in the IP address of the domain name server
The DNS server IP address of the Academy of Trade: 210.35.72.1
The DNS server IP address of Shanghai Telecom:
202.96.199.133 202.96.0.133
Find the local DNS server
If you don't know the local DNS server
Find the local DNS server.
If you don't know the IP address of your local DNS server, you can get it by the following methods:
For Windows 2000/XP, click Windows "Start"|"Programs"|"Accessories"|"Programs"|"Programs"|"Programs"|"Programs"|"Programs"|"Programs"|"Programs"|"Programs". "Accessories"|"Command Prompt", open the Command Prompt window, execute the "ipconfig /all" command, the listed information will contain The "DNS Servers" IP address information will be included in the list.
For Windows 98, you can run the "winipcfg" command from the Windows Start menu. From the pop-up dialog box, "Details" in the "DNS servers" column to view.
Email applications
News Group
news.webking.com.cn
news.sta.net.cn
news.zj.cninfo.net
Subscribe to free e-magazines (Mailing List)
Subscribe to free e-magazines (Mailing List)
Mailing List
Subscribe to free e-magazines (Mailing List)
Subscribe to free e-magazines (Mailing List)
Mailing List
Mailing List
Subscribe to free e-mags. Mailing List)
www.tom.com/maillist
mlist.163.com
Mailing Cards
cards.163.com
Practice
Put your teacher's E-mail address and your other addresses in the address book!
Send a letter using OE
To:
Lessons 1,2: slx@shift.edu.cn
Lessons 3,4: slx1@shift.edu.cn
Cc: Yourself and your other e-mail addresses
Cc: 1,1,2: slx1@shift.edu.cn
Cc: Yourself and your other addresses
Bcc:
1st Lesson 1,2: pc@shift.edu.cn
Lesson 3,4: pc1@shift.edu.cn
Topic: Exercise 2, Machine 05, Zhang San
Exercise
Sending a letter using OE (continued from previous page)
Note that the body of the letter must be in plain text
Send the "Shooting Eagle" letter by the machine number of the computer you are using. The title and the first 200 words of "The Legend of the Eagle Shooting Heroes" (minus 40 for 41-80, minus 80 for 80 or more) should be the body of the e-mail, and the name and major in Chinese characters at the end of the message
Attach the picture on the bottom right corner of the homepage of the College of Foreign Trade as an attachment
Check it out!
Check your email and send it!
Practice
Create a folder Teacher in OE
Establish a mail rule to automatically put emails from teachers into the Teacher folder
Save an email as a file
Comparison of OE with other mail sending and receiving software
Advantages of Foxmail
Remote mailbox management
These are the advantages of Foxmail. Remote mailbox management
Access password function
Email express forwarding function
Eight
About network firewall
Disconnecting (restoring) network
System settings
Customized security level
Detailed information
Procedure rules
Security logs
Computer network
Security logs
On the other hand, OE has the advantage of being able to send and receive emails. p>
Computer network
A collection of autonomous computer interconnections linked on the basis of network protocols for the purpose of ****ing resources and communicating with each other
Function: ****ing resources
Means of communicating (e-mail, collaborative work)
Network classification
Local Area Network (LAN, Local Area Network)
Small area, an office or a building
Wide Area Network (WAN, Wide Area Network)
Covering tens of kilometers or hundreds of kilometers or even the whole planet
Metropolitan Area Network (MAN, Metropolitan Area Network)
Computer network covering a city
Network topology
Physical connection of computers
Bus type
One computer sends out a message, which is received by all the computers on the network
Only one of them actually receives it (the destination address)
Advantages: simplicity, easy to use and master, fewer cables used.
Disadvantages: low efficiency, difficult to maintain
Network topology: bus
Network topology
Star
HUB hub forwarding
Advantages: easy to expand, high reliability, easy to maintain
Disadvantages: HUB failure, the network is paralyzed
More cables used
Network topology: star
Network topology
Ring
Token transmission, token loop
Get a token to send information
Advantages: each computer has a token access, no one computer can monopolize the network, fair **** to enjoy the network resources
Disadvantages: poor reliability. Troubleshooting difficulties, increase or decrease the number of computers interfering with network operation
Network topology: ring
Network adapter
Network adapter → network card, MAC address
Inserted into the computer's motherboard slot
Motherboard integration
Connected to the network type Ethernet, ring
Transmission media (network cable) Type RJ45, BNC
Type of bus used by the computer ISA, PCI
Modem/Demodulator Modom
Telephone line
Modom
ISDN Modom
ADSL Modom
Cable line
CABLE Modom
Power cable
Power Modom ,
Community leased line FTTB+LAN
Wireless
Wireless modom
Transmission media (1)
Transmission media→ Cable media, wireless media
Cable media
Twisted-Pair Cable
Unshielded Twisted-Pair (UTP, Unshielded Twisted-Pair)
Pairs of intertwined wires encapsulated in a plastic casing
Category III cable: 10 Mbps
Category V cable: 100 Mbps
Connection distance: 100 meters. Within
Shielded Twisted Pair (STP, Shielded Twisted-Pair)
Outside a layer of shielding, 500Mbps, high cost
Transmission Media (2)
Coaxial Cable
Core copper wires in the center, the outside of the insulation, and outside the outside of the metal mesh composed of the shielding, and the outside of the casing
10Mbps
Core copper wires, outside the insulation, outside the metal mesh composed of the shielding, and outside the outside of the casing
Coaxial cable
10Mbps, hundreds of meters, cheap
Optical fiber
100Mbps to 2Gbps
Thousands of meters, good confidentiality
Wireless media
Radio systems, terrestrial microwave systems, satellite microwave systems, infrared transmission systems
Twisted-pair
Optical fiber
Network connection
Network connection equipment:
Hub
Since the signal in the network transmission medium has attenuation and noise, so that the useful data signals become weaker and weaker, so in order to ensure the integrity of the useful data, and within a certain range of transmission, the use of a repeater to the weak signals received separation, and regeneration and amplification in order to maintain the same as the original data.
Repeater (Repeater)
Hub (Hub can be said to be a special kind of repeater, as the central node between the network transmission medium, it overcomes the defects of the medium single channel. Hub as the center of the advantage is: when a line or a node in the network system fails, will not affect the normal work of other nodes on the network. Hubs can be divided into passive (Passive) hubs, active (Active) hubs and intelligent (Intelligent) hubs.
Switch (Switch)
Network switching technology a structured network solution. It is the development of computer networks to high-speed transmission stage and the emergence of a new form of network applications. Make the existing network technology through the switching equipment to improve performance.
Network Connectivity
Interconnection Devices:
Bridge
Bridge is a bridge that establishes a connection between a LAN and another LAN