What opportunities does the drug provide to the user? What is the basis of LS software? What is a peer-to-peer LAN? What is a LAN server? What is a LAN workstation? What additional features are provided to users when working on k.
Local computer networks
When working on personal computer V offline mode users can exchange information (programs, documents, etc.) using floppy disks, optical disks and flash memory. However, moving storage media between computers is not always possible and can take quite a lot of time. for a long time.
The creation of computer networks is caused by a practical need quick access to information resources of other computers, as well as printers and other peripheral devices.
A local network (Fig. 6.2) connects computers installed at a relatively short distance from each other (in the same room or building).
For example, computers in a school computer lab are usually connected to a local network, and in a school building several dozen computers installed in subject rooms can be connected to a local network.
Peer-to-peer and server-based networks. In small local networks, all computers usually have equal rights, i.e., users independently decide which resources of their computer (disks, folders or connected printers) to make available to other network users. After this, users working on other computers on the network can use the resources of someone else's computer as if they were their own. As a result, the main disadvantage of such peer-to-peer local networks is the poor security of information from unauthorized access.
In order to ensure greater information security, one of the computers local network can be distinguished as servers, which usually stores the most important information. The rules for access to this information are set by one person - network administrator.
Folder Network Neighborhood. Computers connected to the local network are included in the folder Network environment hierarchical file system(Fig. 6.3).
Click on the icon Network environment, located on Desktop, opens a window containing folders of computers connected to the local network.
Each of the network computers is also a folder, which in turn contains disk folders. If access to the disks and folders of the computer or to the connected printer is granted, then any network user can use them as their own (copy, delete or rename folders, print to a printer).
Each computer connected to a local network must have a network card (Fig. 6.4), the main function of which is to transmit and receive information from the network.
Connecting desktop computers is usually done using cable (electrical or optical). Often used to connect laptops and pocket computers wireless connection, in which data transmission is carried out using electromagnetic waves.
Security questions
1. What additional features are provided to users when working on computers connected to a local network, compared to working on a standalone computer?
2. What is the difference between peer-to-peer LANs and server-based networks?
Tasks for independent completion
6.2. Selective response task. The Network Places folder contains:
1) folders of computers connected to the local network;
2) local computer disk folders;
3) disk folders with open access all computers connected to the local network;
4) folders of all disks of all computers connected to the local network.
Municipal budgetary educational institution
Vishnevskaya secondary school No. 2
Lesson summary on the topic:
"Local computer networks"
for 9th grade
teacher Belousova Natalya Vyacheslavovna
Goals:
Educational:
- introduce the concept of local computer network,
- teach how to transfer data over a local network;
Developmental:
- develop cognitive interest,
- development of group work skills,
- computer skills, self-control;
Educating:
- education of accuracy, discipline, perseverance.
Lesson progress
1. Organizational moment.
Hello, please sit down. Let's get ready for active work, put pens and notebooks in front of us and concentrate. Let's start the lesson.
2. Checking homework.Frontal survey. Solving problems using options.
In the last lesson we started studying communication technologies. Let's review the material.
3. Preparing students for active and conscious learning of new material.
When working on a personal computer in offline mode, users can exchange information (programs, documents, etc.) using optical disks and flash memory. However, moving storage media between computers is not always possible and can take quite a long time. It was necessary to look for ways to solve this problem.
4. Explanation of new material.
The creation of computer networks is caused by the practical need of users of computers remote from each other for the same information, quick access to the information resources of other computers, as well as printers and other peripheral devices. Networks provide users with the opportunity to even simultaneously process the same documents on computers located at a relatively short distance.
Recording the topic in a notebook.Today in class we will get acquainted with the structure of local computer networks.
After studying the topic, you will learn
- what's happened computer network;
- about the types, structure, principles of functioning of a computer network;
- what hardware and software are required for the functioning of computer networks;
- how to exchange data on a local network.
A COMPUTER NETWORK is a system of computers connected by information transmission channels.
A local network (within a premises, an enterprise) allows users not only to quickly exchange information, but also to more efficiently use the resources of networked computers: external memory, printing device, scanner and others technical devices, as well as software.
Global networks connect many local networks, as well as autonomous user computers. The size of global networks is not limited. There are corporate, national and international global networks.
A local network is the connection of two or more computers, allowing them to work together with programs and data.
(Write in a notebook.) LOCAL NETWORKS are small computer networks operating within one room, one enterprise.
If there are no special computers on the local network designed to manage the network, then the network is called peer-to-peer. Users independently decide which resources of their computer to make available to other network users. Such networks have one drawback: poor security of information from unauthorized access.
To ensure greater security, one computer is allocated on the local network, on which the most important information is usually stored.
Such a computer is called a server. Access to information on the server is controlled by one person - the network administrator.
General scheme Connecting computers to a network (topology) can be different.
A variant of connecting computers when a cable runs from one computer to another, connecting computers in series and peripherals between themselves is called LINEAR BUS. If each computer is connected to a separate cable from one central node, then a local network of the STAR type is implemented. Typically, with this connection scheme, the central node is a more powerful computer.
There are other MODELS OF DIFFERENT LAN CONFIGURATIONS. A detailed analysis of each of them in class will take a lot of time. I suggest preparing a message for the next lesson.
Local network computers are usually located close to each other, use a common set of network equipment and are managed by a single package software.
Local networks can be either wired or wireless. IN wired networks The connection is made using twisted pair. Wireless ones use an access point as a central network device, and each computer must have a special Wi-Fi type wireless network card installed.
5. Consolidation of the studied material. Practical work.
Show students the location of the network folder with the task: “Network environment - share to school”; it contains the folder “9th grade” - “Communication technologies” - “PR. How is a local network structured?
Each student at the computer answers a question from the list. (The teacher distributes prepared questions on sheets of paper.) He needs to type the question given by the teacher in Microsoft Office Word and save it in the network folder “Works at school” - “Local computer network” under your last name. The teacher checks the finished files on his computer.
6. Home. Exercise. Theory- http://www.5byte.ru/9/0033.php.
Complete in notebook or upload towww.dnevnik.ru
7. Summing up. Grading. Reflection.
Do you agree that
- Local networks These are associations of computers concentrated in a small area, usually within a radius of no more than 1–2 km.(Yes)
- In fiber optic cables, data can be transmitted in analog rather than digital form.(No)
- A user of a peer-to-peer network can have access to the resources of all computers connected to it if these resources are not protected from unauthorized access)(Yes).
- In a star topology, if a server fails, the network continues to function.(No)
- Access to information on the server is controlled by one person - the network administrator.(Yes)
- IN operating system Windows computers, connected to the local network are displayed in the Network Places folder.(Yes)
Red - today I didn’t learn anything new, nothing was clear to me, new material I won't need it;
Yellow - I learned something new, I didn’t understand everything, I will put the new material into practice;
Green - I was interested, I learned a lot of new things, I will put the material into practice in the next lessons.
Practical work
How does a computer network work?
When working on a personal computer in offline mode, users can exchange information (programs, documents, etc.) using floppy disks, optical disks and flash memory. A system of computers connected by information transmission channels is calledcomputer network.
The creation of computer networks is caused by the practical need for quick access to the information resources of other computers, as well as printers and other peripheral devices.
Local networks
Small computer networks operating within one room, one enterprise, are called local networks ( LS).
Local Area Networks (LAN)- these are associations of computers concentrated in a small area, usually within a radius of no more than 1–2 km, although in some cases a local network can be more extensive, for example, several tens of kilometers. In general, a local network is a communication system owned by one organization.
In many schools, computer science classrooms are equipped with local networks.
Every computer or printer connected to a local network must have a network card. The main function of the network card is to transmit and receive information from the network.
Local networks can be either wired or wireless. In wired networks, the connection is made using different types cables
There are two types of coaxial cable: thin and thick. These types of cable are similar to standard television cable.
"Twisted pair"is a copper-based cable that combines one or more pairs of conductors in a sheath. Each pair consists of two insulated copper wires twisted around each other. Cables of this type often differ greatly in the quality and ability to transmit information.
Shielded twisted pair(Shielded Twisted Pair,STP)Well protects transmitted signals from external radiation, and also reduces power loss in the cable in the form of radiation. The presence of a screen requires high-quality grounding during installation work, which complicates and increases the cost of cable systems.
Unshielded Twisted Pair (UTP) cableare currently the main data transmission medium for non-optical technologies. Good electrical and mechanical characteristics, combined with ease of installation and relatively low cost, make UTP cable ideal for building a horizontal system.
Optical cablecan transmit data with very high throughput. Optical fiber has a high capacity for transmitted data and is resistant to electromagnetic and radio frequency interference. Made from a bundle of glass or plastic strands, fiber optic cable uses light to transmit data.
Fiber optic networkhas a number of advantages over a conventional copper cable network (although a fiber-optic network is more expensive, and fiber is a more fragile material; in addition, fiber-optic cable is more difficult to split than copper).
Firstly , Fiber optic networks carry large amounts of data due to their higher bandwidth.
Secondly , fiber optic cables are thinner and lighter than copper cables and are more noise resistantcompared to them.
Thirdly , data can be transmitted over them in digital rather than analog form.
Fourth , fiber optic cables are free of electromagnetic radiation, which is ideal for meeting the stringent standards required of today's television and computer applications.
All of these advantages are ideally suited to the requirements for transmitting radio and television signals.
On wireless networksAn access point is used as a central network device, and each computer must have a special Wi-Fi-type wireless network card installed.
If all computers on the network have equal rights, that is, the network consists only of user workstations, then it is called a peer-to-peer network.
Peer-to-peer networks are used to implement the first of the noted goals - file sharing. Each computer on such a network has its own name.
More often LAN with dedicated serverare organized according to the following principle: there is one central machine, which is called a file server. Local network users are usually called a work group, and the computers they work on are calledworkstations.
The central machine has large disk memory. It stores software and other information in the form of files that can be accessed by network users.
The name "server" comes from English server and is translated as “service device”.
Server computer -it is a machine that distributes shared resources among many users.
There are two main goalsusing local networks:
1) file sharing between network users;
2) use of shared resources available to all network users: large disk space, printers, centralized database, software and others.
Questions for practical work
- What additional features are available to users when working on computers connected to a local network, compared to working on a standalone computer?
- At what distance are computers usually located on a local network?
- What is the difference between peer-to-peer LANs and server-based networks?
- The principle of organizing a local network with a dedicated server?
- What types of local networks do you know?
- What device is needed to connect a computer to a local network?
- What is the feature of copper based cable?
- How does shielded twisted pair differ from unshielded cable?
- What are the advantages of a fiber optic network?
- What is the operating principle wireless networks?
- What are local networks used for?
standalone computer?
A COMPUTER NETWORK is a system of computers connected by information transmission channels. A local network (within a premises, an enterprise) allows users not only to quickly exchange information, but also to more efficiently use the resources of networked computers: external memory, printing device, scanner and other technical devices, as well as software. Global networks connect between many local networks, as well as stand-alone user computers. The size of global networks is not limited. There are corporate, national and international global networks. A local network is the connection of two or more computers, allowing them to work together with programs and data. LOCAL NETWORKS are small computer networks operating within one premises, one enterprise. If there are no special computers on the local network designed to manage the network, then the network is called peer-to-peer. Users independently decide which resources of their computer to make available to other network users. Such networks have one drawback: poor security of information from unauthorized access. To ensure greater security, one computer is allocated on the local network, on which the most important information is usually stored. Such a computer is called a server. Access to information on the server is controlled by one person - the network administrator. The general scheme for connecting computers to the network (topology) can be different. A variant of connecting computers, when a cable runs from one computer to another, sequentially connecting computers and peripheral devices to each other, is called LINEAR BUS . If each computer is connected to a separate cable from one central node, then a local network of the STAR type is implemented. Typically, with this connection scheme, the central node is a more powerful computer. There are other MODELS OF DIFFERENT LOCAL NETWORK CONFIGURATIONS. A detailed analysis of each of them in class will take a lot of time. I suggest preparing a message for the next lesson. Local network computers are usually located close to each other, use a common set of network equipment and are controlled by the same software package. Each computer or printer connected to the local network must have a network card. The main function of a network card is to transmit and receive information from the network. Local networks can be either wired or wireless. In wired networks, the connection is made using twisted pair cables. Wireless ones use an access point as a central network device, and each computer must have a special Wi-Fi type wireless network card installed. In the operating room Windows system computers connected to the local network are displayed in the Network Neighborhood folder.
Documents in the archive:
o Local computer networks topic lesson,
o Computer science and ICT subject,
o Ugrinovich N.D. Computer science and ICT: textbook for grade 9 / N.D. Ugrinovich.-2nd ed., revised. - M.: BINOM. Knowledge Laboratory, 2009.-295 p. : ill.
www.5byte.ru – “Informatics for five” (Informatics and ICT)
www.klyaksa.net - Information and educational portal for computer science and ICT teachers “Computer science and information and communication technologies at school”
http://www.videouroki.net - “Video lessons on the Internet”
‹ ›
Document title Lesson summary.doc
Municipal budgetary educational institution
“Secondary school No. 18 named after Hero of the Soviet Union
Eduard Dmitrievich Potapov"
Lesson summary on the topic:
"Local computer networks"
for 9th grade
teacher Zatsepina Elena Mikhailovna
Goals:
Educational:
introduce the concept of local computer network,
teach how to transfer data over a local network;
Developmental:
develop cognitive interest,
development of group work skills,
computer skills, self-control;
Educating:
education of accuracy, discipline, perseverance.
Lesson progress
1. Organizational moment.
Hello, please sit down. Let's get ready for active work, put pens and notebooks in front of us and concentrate. Let's start the lesson.
2. Checking homework. Frontal survey. Solving problems using options.
In the last lesson we started studying communication technologies. Let's review the material.
3. Preparing students for active and conscious learning of new material.
When working on a personal computer in offline mode, users can exchange information (programs, documents, etc.) using optical disks and flash memory. However, moving storage media between computers is not always possible and can take quite a long time. It was necessary to look for ways to solve this problem.
4. Explanation of new material.
The creation of computer networks is caused by the practical need of users of computers remote from each other for the same information, quick access to the information resources of other computers, as well as printers and other peripheral devices. Networks provide users with the opportunity to even simultaneously process the same documents on computers located at a relatively short distance.
Recording the topic in a notebook. Today in class we will get acquainted with the structure of local computer networks.
After studying the topic, you will learn
what is a computer network;
about the types, structure, principles of functioning of a computer network;
what hardware and software are required for the functioning of computer networks;
how to exchange data on a local network.
A COMPUTER NETWORK is a system of computers connected by information transmission channels.
A local network (within a premises or an enterprise) allows users not only to quickly exchange information, but also to more efficiently use the resources of networked computers: external memory, printing device, scanner and other technical devices, as well as software.
Global networks connect many local networks, as well as autonomous user computers. The size of global networks is not limited. There are corporate, national and international global networks.
A local network is the connection of two or more computers, allowing them to work together with programs and data.
(Write in a notebook.) LOCAL NETWORKS are small computer networks operating within one room, one enterprise.
If there are no special computers on the local network designed to manage the network, then the network is called peer-to-peer. Users independently decide which resources of their computer to make available to other network users. Such networks have one drawback: poor security of information from unauthorized access.
To ensure greater security, one computer is allocated on the local network, on which the most important information is usually stored.
Such a computer is called a server. Access to information on the server is controlled by one person - the network administrator.
The general scheme for connecting computers to a network (topology) may be different.
A variant of connecting computers, when a cable runs from one computer to another, sequentially connecting computers and peripheral devices to each other, is called LINEAR BUS. If each computer is connected to a separate cable from one central node, then a local network of the STAR type is implemented. Typically, with this connection scheme, the central node is a more powerful computer.
There are other MODELS OF DIFFERENT LAN CONFIGURATIONS. A detailed analysis of each of them in class will take a lot of time. I suggest preparing a message for the next lesson.
Computers on a local network are usually located close to each other, use a common set of network equipment, and are managed by the same software package.
Local networks can be either wired or wireless. In wired networks, the connection is made using twisted pair cables. Wireless ones use an access point as a central network device, and each computer must have a special Wi-Fi type wireless network card installed.
In the Windows operating system, computers connected to the local network are displayed in the Network Neighborhood folder.
5. Consolidation of the studied material. Practical work.
Show students the location of the network folder with the task: “Network environment - share on school”, it contains the folder “9th grade” - “Communication technologies” - “PR. How is a local network structured?
Each student at the computer answers a question from the list. (The teacher distributes prepared questions on sheets of paper.) He needs to type the question given by the teacher into Microsoft Office Word and save it in the network folder “Works at school” - “Local computer network” under your last name. The teacher checks the finished files on his computer.
6. Home. Exercise. Theory- .
Complete in notebook or upload to
7. Summing up. Grading. Reflection.
Do you agree that
Local networks These are associations of computers concentrated in a small area, usually within a radius of no more than 1–2 km. (Yes)
In fiber optic cables, data can be transmitted in analog rather than digital form. (No)
A user of a peer-to-peer network can have access to the resources of all computers connected to it if these resources are not protected from unauthorized access) (Yes).
In a star topology, if a server fails, the network continues to function. (No)
Access to information on the server is controlled by one person - the network administrator. (Yes)
In the Windows operating system, computers connected to the local network are displayed in the Network Neighborhood folder. (Yes)
Red - today I didn’t learn anything new, I didn’t understand anything, the new material won’t be useful to me;
Yellow - I learned something new, I didn’t understand everything, I will put the new material into practice;
Green - I was interested, I learned a lot of new things, I will put the material into practice in the next lessons.
How does a computer network work?
When working on a personal computer in offline mode, users can exchange information (programs, documents, etc.) using floppy disks, optical disks and flash memory. A system of computers connected by information transmission channels is called computer network.
The creation of computer networks is caused by the practical need for quick access to the information resources of other computers, as well as printers and other peripheral devices.
Local networks
Small computer networks operating within one room, one enterprise, are called local networks ( PM).
Local Area Networks (LAN) - these are associations of computers concentrated in a small area, usually within a radius of no more than 1–2 km, although in some cases a local network can be more extensive, for example, several tens of kilometers. In general, a local network is a communication system owned by one organization.
In many schools, computer science classrooms are equipped with local networks.
Every computer or printer connected to a local network must have a network card. The main function of the network card is to transmit and receive information from the network.
Local networks can be either wired or wireless. In wired networks, the connection is made using different types of cables.
There are two types of coaxial cable : thin and thick. These types of cable are similar to standard television cable.
"Twisted Pair" (twisted pair) is a copper-based cable that combines one or more pairs of conductors in a sheath. Each pair consists of two insulated copper wires twisted around each other. Cables of this type often differ greatly in quality and information transmission capabilities.
Shielded twisted pair(Shielded Twisted Pair,STP) Well protects transmitted signals from external radiation, and also reduces power loss in the cable in the form of radiation. The presence of a screen requires high-quality grounding during installation work, which complicates and increases the cost of cable systems.
Cable tounshielded twisted pair(Unshielded Twisted Pair,UTP) are currently the main data transmission medium for non-optical technologies. Good electrical and mechanical characteristics, combined with ease of installation and relatively low cost, make UTP cable ideal for building a horizontal system.
Optical cable can transmit data with very high throughput. Optical fiber has a high capacity for transmitted data and is resistant to electromagnetic and radio frequency interference. Made from a bundle of glass or plastic strands, fiber optic cable uses light to transmit data.
Fiber optic network has a number of advantages over a conventional copper cable network (although a fiber-optic network is more expensive, and fiber is a more fragile material; in addition, fiber-optic cable is more difficult to split than copper).
Firstly, Fiber optic networks carry large amounts of data due to their higher bandwidth.
Secondly, fiber optic cables are thinner and lighter than copper cables and are more noise resistant than them.
Thirdly, data can be transmitted over them in digital rather than analog form.
Fourth, fiber optic cables are free of electromagnetic radiation, which is ideal for meeting the stringent standards required of today's television and computer applications.
All of these advantages are ideally suited to the requirements for transmitting radio and television signals.
On wireless networks An access point is used as a central network device, and each computer must have a special Wi-Fi-type wireless network card installed.
If all computers on the network have equal rights, that is, the network consists only of user workstations, then it is called a peer-to-peer network.
Peer-to-peer networks are used to implement the first of the noted goals - file sharing. Each computer on such a network has its own name.
More oftenLAN with dedicated server are organized according to the following principle: there is one central machine, which is called a file server. Local network users are usually called a work group, and the computers they work on are calledworkstations.
The central machine has large disk memory. It stores software and other information in the form of files that can be accessed by network users.
The name "server" comes from English server and is translated as “service device”.
Server computer - it is a machine that distributes shared resources among many users.
There are two main goals using local networks:
1) file sharing between network users;
2) use of shared resources available to all network users: large disk space, printers, centralized database, software and others.
Questions for practical work
What additional features are available to users when working on computers connected to a local network, compared to working on a standalone computer?
At what distance are computers usually located on a local network?
What is the difference between peer-to-peer LANs and server-based networks?
The principle of organizing a local network with a dedicated server?
What types of local networks do you know?
What device is needed to connect a computer to a local network?
What is the feature of copper based cable?
How does shielded twisted pair differ from unshielded cable?
What are the advantages of a fiber optic network?
What is the operating principle of wireless networks?
What are local networks used for?
‹ ›
Document title Local computer networks.pptx
‹‹ ‹
1 of 32
› ››Description of the presentation by individual slides:
Slide no. 1
Slide description:
Repetition of the topic “Data transmission”, their throughput (information transfer speed). the amount of information that can be transmitted over it per unit of time. The main characteristic of information transmission channels is... 2. The channel capacity is...
Slide no. 2
Slide description:
Review of the topic “Data transmission” in bits per second (bps) and multiples of Kbps and Mbps. However, sometimes the unit is byte per second (byte/s) and its multiples KB/s and MB/s. 2.I = v*t I – quantity transmitted information; v – channel capacity (information transmission speed); t – information transmission time. 4.Usually throughput is measured by 3. 1.I = k*i 3.I = i*x*y 4.N = 2
Slide no. 3
Slide description:
Solving GIA problems Option 2 A 4 KB file is transmitted through a connection at a speed of 2048 bits per second. Determine the file size (in bytes) that can be transferred in the same time over another connection at 512 bits per second. In your answer, indicate one number - the file size in bytes. There is no need to write units of measurement. Option 1 A 9 KB file is transferred over some connection at a speed of 1536 bits per second. Determine the file size (in bytes) that can be transferred in the same time over another connection at 512 bits per second. In your answer, indicate one number - the file size in bytes. There is no need to write units of measurement.
Slide no. 4
Slide description:
Answers to GIA problems Option 1 I1=V1 x t1, t=I1/V1= =9 Kbyte/1536 bit/s = =9 Kbyte x1024 byte x x 8 bit/1536 bit/s= =73728 bit/1536 bit/s= =48 s, I2=V2 x t2=512bit/s*48s= =24576 bits=3072 (bytes) Option 2 I1=V1 x t1, t=I1/V1= =4 KB/2048 bit/s= =4 KB x1024 byte x x 8 bit/2048 bit/s = =32768 bit/2048 bit/s= =16 s, I2=V2 x t2= 512 bit/s*16 s= =8192 bit = 1024 (byte)
Slide no. 5
Slide description:
When working on a PC in offline mode, users can exchange information only by copying it to floppy disks or CD ROM drives. MOving DISKS BETWEEN COMPUTERS CAN TAKE A LONG TIME!
Slide no. 6
Slide description:
Local computer networks Computer telecommunications MBOU Secondary School No. 18 named after E.D. Potapova
Slide no. 7
Slide description:
After studying the topic, you will learn what a computer network is; about the types, structure, principles of functioning of a computer network; what hardware and software are required for the functioning of computer networks; how to exchange data on a local network.
Slide no. 8
Slide description:
What is a computer network A COMPUTER NETWORK is a system of computers connected by information transmission channels. A local network (within a premises or an enterprise) allows users not only to quickly exchange information, but also to more efficiently use the resources of networked computers: external memory, printing device, scanner and other technical devices, as well as software. Data transmission line Local networks Global networks Global networks connect many local networks, as well as autonomous user computers. The size of global networks is not limited. There are corporate, national and international global networks.
Slide no. 9
Slide description:
LOCAL NETWORKS (LAN) LOCAL NETWORKS are small computer networks operating within one room, one enterprise. A user of a peer-to-peer network can have access to the resources of all computers connected to it (if these resources are not protected from unauthorized access). A network with a dedicated server is organized according to the following principle: there is one central computer (server) and many smaller computers connected to it. powerful computers- workstations. The central machine usually has a larger volume external memory, devices are connected to it that are not on workstations (printer, scanner, modem for connecting to global network etc.). P2P NETWORK NETWORK WITH DEDICATED SERVER Server
Slide no. 10
Slide description:
Bus A single cable is used along which all computers on the network are connected. A terminator is needed to absorb the transmitted signal at the ends. Simplicity If one computer fails, this will not affect the operation of the others. At any given time, only one computer can transmit data. A broken cable leads to the termination of the network. If there are a large number of computers, the network works slowly. Disadvantages: Advantages: terminator terminator Topology networks - general computer connection diagram on a network
Slide no. 11
Slide description:
Star Server Disadvantages: Advantages: Network management is centralized (there is a special central device (hub), from which “rays” go to each computer, i.e. each computer is connected to its own cable). If one computer fails, the network remains operational. If a server fails, the network stops functioning. For large networks, cable consumption increases significantly.
Slide no. 12
Slide description:
Ring Signals are transmitted along the ring in one direction and pass through each computer (closed network). Advantages: Disadvantages: The cable does not have a free end and therefore does not need a terminator. Each computer amplifies the signals by transmitting them to the next computer. If one computer fails, the entire network stops functioning.
Slide no. 13
Slide description:
Hardware networks To organize a local network, you need to install a network card in each PC and connect all computers using a special cable.
Slide no. 14
Slide description:
Cables Coaxial cable - transmission speed up to 10 Mbit/s Twisted pair - transmission speed up to 100 Mbit/s Network hardware Fiber optic cable - transmitting information over long distances Coaxial cable comes in two types: thin and thick. These types of cable are similar to standard television cable. A twisted pair is a copper-based cable that combines one or more pairs of conductors in a sheath. Each pair consists of two insulated copper wires twisted around each other. Cables of this type often differ greatly in quality and information transmission capabilities. Shielded Twisted pair (Shielded Twisted Pair, STP) well protects transmitted signals from external radiation, and also reduces power losses in the cable in the form of radiation. The presence of a screen requires high-quality grounding during installation work, which complicates and increases the cost of unshielded twisted cable systems. Unshielded Twisted Pair (UTP) is currently the main data transmission medium for non-optical technologies. Good electrical and mechanical characteristics combined with ease of installation and relatively low cost make UTP cable ideal for building a horizontal system. Optical cable can transmit data with. very high throughput. Optical fiber has a high capacity for transmitted data and is resistant to electromagnetic and radio frequency interference. Made from a bundle of glass or plastic strands, fiber optic cable uses light to transmit data. A fiber-optic network has several advantages over a conventional copper network (although fiber-optic networks are more expensive, and fiber-optic cables are more fragile; fiber-optic cables are also more difficult to split than copper cables). First, fiber optic networks carry large amounts of data due to their higher bandwidth. Secondly, fiber optic cables are thinner and lighter than copper cables and are more resistant to interference than them. Thirdly, data can be transmitted digitally rather than analogue. Fourth, fiber optic cables contain no electromagnetic radiation, which is ideal for meeting the stringent standards required of today's television and computer applications. All of these advantages are ideally suited to the requirements for transmitting radio and television signals.
Slide no. 26Slide description:
Questions of practical work What additional opportunities are provided to users when working on computers connected to a local network, compared to working on a stand-alone computer? At what distance are computers usually located on a local network? What is the difference between peer-to-peer LANs and server-based networks? The principle of organizing a local network with a dedicated server? What types of local networks do you know? What device is needed to connect a computer to a local network? What is the feature of copper based cable? How does shielded twisted pair differ from unshielded cable? What are the advantages of a fiber optic network? What is the operating principle of wireless networks? What are local networks used for?
Slide no. 27
Slide description:
Homework Theory - http://www.5byte.ru/9/0033.php Do it in a notebook or upload to www.dnevnik.ru http://files.dnevnik.ru/file.aspx?user=372034&file=14527892
Slide no. 28
Slide description:
Do you agree that Local networks are associations of computers concentrated in a small area, usually within a radius of no more than 1–2 km. In fiber optic cables, data can be transmitted in analog rather than digital form. A user of a peer-to-peer network can have access to the resources of all computers connected to it if these resources are not protected from unauthorized access). In a star topology, if a server fails, the network continues to function. Access to information on the server is controlled by one person - the network administrator. In the Windows operating system, computers connected to the local network are displayed in the Network Neighborhood folder.
Slide no. 29
Slide description:
Lesson summary A local network unites computers installed in one room (for example, a school computer lab consisting of 8-12 computers) or in one building (for example, in a school building several dozen computers installed in different subject rooms can be combined into a local network ). Local Area Network (LAN) is a computer network covering a relatively small area. Each computer connected to the local network must have a special card (network adapter). Computers between each other ( network adapters) are connected, for example, using cables. Local networks can be peer-to-peer or with a dedicated server. General computer connection diagram (topology): bus, star.
Slide description:
Information resources http://www.5byte.ru/9/0033.php http://www.klyaksa.net/ http://www.nsportal.ru/ermolaeva-irina-alekseevna http://delay-s- nami.ru/?p=225 http://school-collection.edu.ru/
Slide no. 32
Slide description:
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