Report on industrial practice in the computer center of the USMTU (computer networks. classification of computer networks) - abstract. Practice report: Design of an educational local computer network Report on industrial practice computer networks

INTRODUCTION

Practice goals:

Consolidation of theoretical knowledge acquired during the study of disciplines: organization of computers and systems, system software, databases, computer networks and telecommunications, peripheral office equipment;





Familiarization with production processes, including the use of computer technology and information technology;





Studying methods of formation, processing, accumulation and use of information flows in the production process;





Acquiring skills in the use of autonomous and integrated computing systems;





Analysis of achievements and shortcomings in the organization's activities.

Practice topic:

Studying the principles of construction and functioning of a local computer network in a specific organization.

I chose the organization “Snegovik Plus” LLC as the place for my production and technological practice.

Enterprise structure: Director Evgeniy Nikovaevich Masov. He has 20 people under his command: accountant, loaders, drivers, technicians,

sellers.

MAIN PART

General principles of construction and computer architecture;

Principles, methods and methods of integrating hardware and software when creating computer systems, complexes and networks;

Models, methods and forms of organizing the process of developing a software product, technical product;

Basic capabilities of database management systems and their use.

In addition, he must learn:

Use technical and reference literature, sets of standards for the development of software products and technical products;





Use the knowledge and skills acquired during the learning process for competent and technically sound development of a software product or technical product;





Design a software product, technical product;





Develop programs with a modular structure;





Apply methods and means of testing and testing a software product, technical product;





Use debugging tools;

LLC "Snegovik Plus" sells wholesale products in Ulyanovsk.

I completed an internship in the technical department under the guidance of a programmer

Vorlamova N.F. Database management on deliveries and quantities of goods in warehouses is carried out using computers with an operating system Windows 95 or Windows 98 .

In order to save time transferring information from one computer to another, the director of this company decided to create a local network in his organization. The technical department was tasked with laying a network to every computer in the company. The technical department began to complete the task.

First, we had to project on the spot which type of network would be better for us to use a Local Network with a central Server. See Appendix 1

The simplest version of such a network is to connect computers through parallel or serial ports. In this case, there is no need for any additional equipment. There should only be connecting conductors. Such communication between computers is configured within one or several rooms. It is used to transfer data from one computer to another. In this case, you can transfer data without using floppy disks. Any modern operating system shell has software that ensures such data transfer.

In local peer-to-peer computer networks, computers connect to the network through special network adapters, and the functioning of the network is supported by the network operating system. Examples of such operating systems are: Novell Personal Net Ware, Net Ware Line, Windows for Workgroups.

All computers and their operating systems in local peer-to-peer computer networks must be of the same type. Users of this network can transfer data to each other, use shared printers, magnetic and optical disks, etc.

In a local multi-rank computer network, one more powerful computer is used, which is called a server, and other, less powerful ones are called workstations. Servers use special system software that differs from workstation system software.

Main parts of the network.

For our network we used twisted pair cable or coaxial cable Twisted Pair 10BaseT.

Twisted pair connectors

Twisted pair networks include 10BaseT, 100BaseTX, 100BaseT4 networks, and the adoption of the 1000BaseT standard is also very likely.

In network cards of computers, in hubs and on walls there are sockets (jacks), plugs are stuck into them.

Twisted pair connectors

Eight Pin Modular Connector (Plug)

Common name "RJ-45"

Fork with insert

Connectors for 10Base-T

Eight-pin modular connector.

Jack and outlet

Network cards are used to connect the network to a computer.

PCI network card

Combined network card (BNC+RJ45), PCI bus

Simultaneous use of two connectors is not permitted.

PCI slot

There is also a PCI data bus (white connectors). Network cards designed for PCI must be inserted into a PCI slot.

On the computer

Server setup.

Servers

Server functions Windows95(Windows98)

PRACTICE DIARY

practices;

June 17 – Selected literature on the topic of the assignment, studied software (Novell Personal Net Ware, Net Ware Line, Windows for Workgroups.);

CONCLUSIONS:

While at this enterprise I:

Complied with occupational health and safety regulations;





Complied with the rules established for employees of the enterprise, including on issues of labor regulations, fire safety, confidentiality regime, responsibility for the safety of property;





Studied the current standards, technical conditions, job responsibilities, regulations and operating instructions for VT;





Studied the rules of operation and maintenance of military equipment and research facilities available in the unit;





Mastered individual computer programs used in the professional field (Novell Personal Net Ware, Net Ware Line, Windows for Workgroups);





Mastered working with periodicals, abstracts and reference information publications on computer science and computer technology;

Performed tasks provided for by the internship program.

Do not submit your downloaded work to your teacher!

This practice report can be used by you as a sample, in accordance with the example, but with the data of your enterprise, you can easily write a report on your topic.

Content

Introduction

Chapter 1 Concept and classification of computer networks

1.1 Purpose of a computer network

1.2 Classification of computer networks

Chapter 2. Main types of computer networks

2.1 Local area network (LAN)

2.2 Global Area Network (WAN)

Conclusion

List of used literature

Introduction

Russia's entry into the global information space entails the widespread use of the latest information technologies, and first of all, computer networks. At the same time, the user’s capabilities sharply increase and qualitatively change both in providing services to their clients and in solving their own organizational and economic problems.

It is appropriate to note that modern computer networks are a system whose capabilities and characteristics generally significantly exceed the corresponding indicators of the simple sum of the constituent elements of a network of personal computers in the absence of interaction between them.

The advantages of computer networks have led to their widespread use in information systems of the credit and financial sector, government and local governments, enterprises and organizations.

Computer networks and network information processing technologies have become the basis for the construction of modern information systems. The computer should now be considered not as a separate processing device, but as a “window” into computer networks, a means of communication with network resources and other network users.

In recent years, the global Internet has become a global phenomenon. The network, which until recently was used by a limited number of scientists, government officials and employees of educational institutions in their professional activities, has become available to large and small corporations and even to individual users.

The purpose of this coursework is to familiarize yourself with the basics of the construction and operation of computer networks, to study the organization of computer networks. To achieve this goal, it is necessary to solve a number of problems:

Introduction to computer networks, highlighting their features and differences;

Characteristics of the main methods of constructing networks (network topology);

Studying scientific and methodological literature on this issue

Chapter 1 Concept and classification of computer networks

1.1 Purpose of a computer network

The main purpose of computer networks is to share resources and implement interactive communications both within one company and outside it. Resources are data, applications, and peripheral devices such as an external disk drive, printer, mouse, modem, or joystick.

Computers included in the network perform the following functions:

Organization of Internet access

Information transfer control

Providing computing resources and services to network users.

Currently, local computing (LAN) has become very widespread. This is due to several reasons:

Connecting computers into a network allows you to significantly save money by reducing the cost of maintaining computers (it is enough to have a certain disk space on the file server (the main computer of the network) with software products installed on it, used by several workstations);

Local networks allow you to use a mailbox to transfer messages to other computers, which allows you to transfer documents from one computer to another in the shortest possible time;

Local networks, with special software, are used to organize the sharing of files (for example, accountants on several machines can process transactions of the same ledger).

Among other things, in some areas of activity it is simply impossible to do without a LAN. These areas include: banking, warehouse operations of large companies, electronic archives of libraries, etc. In these areas, each individual workstation, in principle, cannot store all the information (mainly due to its too large volume).

A global computer network is a network connecting computers located geographically at great distances from each other. It differs from a local network in having longer communications (satellite, cable, etc.). The global network connects local networks.

The Internet, which once served exclusively research and academic groups whose interests ranged from accessing supercomputers, is becoming increasingly popular in the business world.

1.2 Classification of computer networks

Based on the method of organization, networks are divided into real and artificial.

Artificial networks (pseudo-networks) allow you to connect computers together via serial or parallel ports and do not require additional devices. Sometimes communication in such a network is called communication via a null modem (no modem is used). Self-connection is called null-modem. Artificial networks are used when it is necessary to transfer information from one computer to another. MS-DOS and Windows are equipped with special programs for implementing a null modem connection.

Real networks allow computers to be connected using special switching devices and physical data transmission media.

/> The territorial distribution of networks can be local, global, regional and city.

Local Area Network (LAN) - Local Area Networks (LAN) is a group (communication system) of a relatively small number of computers united by a shared data transmission medium, located in a limited small area within one or more nearby buildings (usually within a radius of no more than 1 -2 km) in order to share the resources of all computers

A global computer network (WAN or WAN - World Area NetWork) is a network connecting computers that are geographically distant from each other. Differs from a local network in more extensive communications (satellite, cable, etc.). The global network connects local networks.

Metropolitan Area Network (MAN - Metropolitan Area NetWork) is a network that serves the information needs of a large city.

Regional - located on the territory of a city or region.

Also, recently experts have identified this type of network as a banking one, which is a special case of the corporate network of a large company. It is obvious that the specifics of banking activities impose strict requirements on information protection systems in the bank’s computer networks. An equally important role when building a corporate network is played by the need to ensure trouble-free and uninterrupted operation, since even a short-term failure in its operation can lead to huge losses.

There are departmental and state networks based on their affiliation. Departmental ones belong to one organization and are located on its territory.

Government networks are networks used in government agencies.

Based on the speed of information transmission, computer networks are divided into low-, medium- and high-speed.

low-speed (up to 10Mbit/s),

medium-speed (up to 100Mbit/s),

high-speed (over 100 Mbit/s);

Depending on the purpose and technical solutions, networks can have different configurations (or, as they also say, architecture, or topology).

In a ring topology, information is transmitted over a closed channel. Each subscriber is directly connected to its two closest neighbors, although in principle it is capable of contacting any subscriber in the network.

In a star-shaped (radial) system, in the center there is a central control computer that sequentially communicates with subscribers and connects them with each other.

In a bus configuration, computers are connected to a common channel (bus), through which they can exchange messages.

In a tree view, there is a “main” computer, to which the computers of the next level are subordinate, etc.

In addition, configurations without a distinct nature of connections are possible; The limit is a fully meshed configuration, where every computer on the network is directly connected to every other computer.

From the point of view of organizing the interaction of computers, networks are divided into peer-to-peer (Peer-to-Peer Network) and dedicated server (Dedicated Server Network).

All computers in a peer-to-peer network have equal rights. Any network user can access data stored on any computer.

Peer-to-peer networks can be organized using operating systems such as LANtastic, Windows "3.11, Novell Netware Lite. These programs work with both DOS and Windows. Peer-to-peer networks can also be organized on the basis of all modern 32-bit operating systems - Windows 9x \ME\2k, Windows NTworkstation version, OS/2) and some others.

Advantages of peer-to-peer networks:

1) the easiest to install and operate.

2) the DOS and Windows operating systems have all the necessary functions that allow you to build a peer-to-peer network.

The disadvantage of peer-to-peer networks is that it is difficult to resolve information security issues. Therefore, this method of organizing a network is used for networks with a small number of computers and where the issue of data protection is not fundamental.

In a hierarchical network, when the network is installed, one or more computers are pre-allocated to manage data exchange over the network and resource distribution. Such a computer is called a server.

Any computer that has access to the server's services is called a network client or workstation.

A server in hierarchical networks is a permanent storage of shared resources. The server itself can only be a client of a server at a higher hierarchy level. Therefore, hierarchical networks are sometimes called dedicated server networks.

Servers are usually high-performance computers, possibly with several parallel processors, large-capacity hard drives, and a high-speed network card (100 Mbit/s or more).

The hierarchical network model is the most preferable, as it allows you to create the most stable network structure and more rationally distribute resources.

Another advantage of a hierarchical network is a higher level of data protection.

The disadvantages of a hierarchical network, compared to peer-to-peer networks, include:

1) the need for an additional OS for the server.

2) higher complexity of network installation and upgrading.

3) The need to allocate a separate computer as a server.

Chapter 2 Main types of computer networks

2.1 Local area network (LAN)

Local networks (LAN computers) connect a relatively small number of computers (usually from 10 to 100, although sometimes much larger ones are found) within one room (a computer classroom), building or institution (for example, a university). The traditional name is a local area network (LAN). ) - rather a tribute to the times when networks were mainly used to solve computing problems; today, in 99% of cases, we are talking exclusively about the exchange of information in the form of texts, graphic and video images, and numerical arrays. The usefulness of the LS is explained by the fact that from 60% to 90% of the information an institution needs circulates within it, without needing to go outside.

The development of drugs was greatly influenced by the creation of automated enterprise management systems (ACS). ACS include several automated workstations (AWS), measuring systems, and control points. Another important field of activity in which drugs have proven their effectiveness is the creation of classroom-based computer technology (KUTT).

Thanks to the relatively short lengths of communication lines (usually no more than 300 meters), information can be transmitted digitally over the LAN at a high transmission speed. Over long distances, this transmission method is unacceptable due to the inevitable attenuation of high-frequency signals; in these cases, it is necessary to resort to additional technical (digital-to-analog conversions) and software (error correction protocols, etc.) solutions.

A characteristic feature of the LAN is the presence of a high-speed communication channel connecting all subscribers for transmitting information in digital form.

There are wired and wireless channels. Each of them is characterized by certain values ​​of parameters that are essential from the point of view of drug organization:

Data transfer rates;

Maximum line length;

Noise immunity;

Mechanical strength;

Convenience and ease of installation;

Cost.

Currently, four types of network cables are commonly used:

Coaxial cable;

Unprotected VitayaPara;

Protected twisted pair;

Fiber optic cable.

The first three types of cables transmit an electrical signal through copper conductors. Fiber optic cables transmit light along glass fibers.

Most networks allow several cable connection options.

Coaxial cables consist of two conductors surrounded by insulating layers. The first layer of insulation surrounds the central copper wire. This layer is braided from the outside with an external shielding conductor. The most common coaxial cables are thick and thin "Ethernet" cables. This design provides good noise immunity and low signal attenuation over distances.

There are thick (about 10 mm in diameter) and thin (about 4 mm) coaxial cables. Having advantages in noise immunity, strength, and league length, a thick coaxial cable is more expensive and more difficult to install (it is more difficult to pull through cable channels) than a thin one. Until recently, thin coaxial cable represented a reasonable compromise between the basic parameters of LAN communication lines and in Russian conditions is most often used for organizing large LANs of enterprises and institutions. However, thicker, more expensive cables provide better data transmission over longer distances and are less susceptible to electromagnetic interference.

Twisted pairs are two wires twisted together at six turns per inch to provide EMI protection and impedance matching. Another name commonly used for such wire is “IBM Type-3.” In the United States, such cables are installed during the construction of buildings to provide telephone service. However, the use of telephone wire, especially when it is already located in the building, can create big problems. First, unprotected twisted pairs are susceptible to electromagnetic interference, such as electrical noise generated by fluorescent lights and moving elevators. Interference can also be caused by signals transmitted in a closed loop along telephone lines along a LAN cable. In addition, poor quality twisted pairs may have a variable number. turns per inch, which distorts the calculated electrical resistance.

It is also important to note that telephone wires are not always laid in a straight line. A cable connecting two adjacent rooms can actually go around half the building. Underestimating the cable length in this case may result in it actually exceeding the maximum permissible length.

Protected twisted pairs are similar to unprotected twisted pairs, except that they use thicker wires and are protected from external influences by the neck of the insulator. The most common type of such cable used in local networks, “IBM type-1” is a secure cable with two twisted pairs of continuous wire. In new buildings, Type-2 cable may be the best option, since it includes, in addition to the data transmission line, four unprotected pairs of continuous wire for transmitting telephone conversations. Thus, “type-2” allows you to use one cable to transmit both telephone conversations and data over a local network.

Protection and careful adherence to the number of twists per inch make rugged twisted pair cable a reliable alternative cabling connection.” However, this reliability comes at an increased cost.

Fiber optic cables transmit data in the form of pulses of light" to glass "wires". Most LAN systems today support fiber optic cabling. Fiber optic cable has significant advantages over any copper cable option. Fiber optic cables provide the highest transmission speeds; they are more reliable because they are not subject to loss of information packets due to electromagnetic interference. Optical cable is very thin and flexible, making it easier to transport than heavier copper cable. Most importantly, however, only optical cable has the bandwidth needed for faster networks in the future.

The price of fiber optic cable is still significantly higher than copper cable. Compared to copper cable, the installation of an optical cable is more labor-intensive, since its ends must be carefully polished and aligned to ensure a reliable connection. However, now there is a transition to fiber-optic lines, which are absolutely immune to interference and are unrivaled in terms of throughput. The cost of such lines is steadily decreasing, technological difficulties The junctions of optical fibers are successfully overcome.

Wireless communications over microwave radio waves can be used to organize networks within large premises such as hangars or pavilions, where the use of conventional communication lines is difficult or impractical. In addition, wireless lines can connect remote segments of local networks at distances of 3 - 5 km (with a wave channel antenna) and 25 km (with a directional parabolic antenna) subject to direct visibility. Organizing a wireless network is significantly more expensive than a conventional one.

To connect computers using LAN communication lines, network adapters (or, as they are sometimes called, network cards) are required. The most famous are: adapters of the following three types:

Of these, the latter have become overwhelmingly widespread in Russia. The network adapter is inserted directly into a free slot on the motherboard of a personal computer and a LAN communication line is connected to it on the rear panel of the system unit. The adapter, depending on its type, implements one or another access strategy from one computer to another.

To ensure coordinated operation in data networks, various communication protocols are used - sets of rules that the transmitting and receiving parties must adhere to for consistent data exchange. Protocols are sets of rules and procedures that govern how some communication occurs. Protocols are the rules and technical procedures that allow multiple computers, when networked, to communicate with each other.

There are many protocols. And although they all participate in the implementation of communication, each protocol has different goals, performs different tasks, and has its own advantages and limitations.

Protocols operate at different levels of the OSI/ISO open systems interconnection model. The functions of a protocol are determined by the level at which it operates. Several protocols can work together. This is the so-called stack, or set, of protocols.

Just as networking functions are distributed across all layers of the OSI model, protocols operate together at different layers of the protocol stack. Layers in the protocol stack correspond to layers of the OSI model. Taken together, the protocols provide a complete description of the functions and capabilities of the stack.

Data transmission over a network, from a technical point of view, must consist of sequential steps, each of which has its own procedures or protocol. Thus, a strict sequence in performing certain actions is maintained.

In addition, all these steps must be performed in the same sequence on each network computer. On the sending computer, actions are performed from top to bottom, and on the receiving computer, from bottom to top.

The sending computer, in accordance with the protocol, performs the following actions: breaks the data into small blocks called packets that the protocol can work with, adds address information to the packets so that the receiving computer can determine that this data is intended for it, prepares the data for transmission through the network adapter card and then via the network cable.

The recipient computer, in accordance with the protocol, performs the same actions, but only in reverse order: receives data packets from the network cable; transmits data to the computer through the network adapter card; removes from the packet all service information added by the sending computer, copies the data from the packet to a buffer - to combine it into the original block, transfers this block of data to the application in the format that it uses.

Both the sending computer and the receiving computer need to perform each action in the same way so that the data received over the network matches the data sent.

If, for example, the two protocols have different ways of breaking up data into packets and adding information (packet sequence, timing, and error checking), then a computer running one of those protocols will not be able to successfully communicate with a computer running the other protocol.

Until the mid-80s, most local networks were isolated. They served individual companies and were rarely combined into large systems. However, when local networks reached a high level of development and the volume of information transmitted by them increased, they became components of large networks. Data transmitted from one local network to another along one of the possible routes is called routed. Protocols that support data transfer between networks along multiple routes are called routed protocols.

Among the many protocols, the most common are the following:

· IPX/SPX and NWLmk;

· OSI protocol suite.

2.2 Wide Area Network (WAN)

WAN (World Area Network) is a global network covering large geographic regions, including both local networks and other telecommunication networks and devices. An example of a WAN is a packet-switched network (Frame relay), through which various computer networks can “talk” to each other.

Today, when the geographical boundaries of networks are expanding to connect users from different cities and states, LANs are turning into a global computer network [WAN], and the number of computers in the network can already vary from tens to several thousand.

Internet is a global computer network covering the whole world. Today the Internet has about 15 million subscribers in more than 150 countries around the world. Every month the size of the network increases by 7-10%. The Internet forms a kind of core that connects various information networks belonging to various institutions around the world with one another.

If previously the network was used exclusively as a medium for transferring files and e-mail messages, today more complex problems of distributed access to resources are being solved. About three years ago, shells were created that support network search functions and access to distributed information resources and electronic archives.

The Internet, which once served exclusively research and academic groups whose interests ranged from access to supercomputers, is becoming increasingly popular in the business world.

Companies are seduced by speed, cheap global communications, ease of collaboration, accessible programs, and a unique Internet database. They view the global network as a complement to their own local networks.

At a low cost (often just a flat monthly fee for the lines or telephone used), users can access commercial and non-commercial information services in the United States, Canada, Australia, and many European countries. In the archives of free access on the Internet you can find information on almost all areas of human activity, from new scientific discoveries to the weather forecast for tomorrow.

In addition, the Internet provides unique opportunities for low-cost, reliable and confidential global communications around the world. This turns out to be very convenient for companies with their branches around the world, transnational corporations and management structures. Typically, using the Internet infrastructure for international communication is much cheaper than direct computer communication via satellite or telephone.

E-mail is the most common Internet service. Currently, approximately 20 million people have an email address. Sending a letter by e-mail is much cheaper than sending a regular letter. In addition, a message sent by e-mail will reach the recipient in a few hours, while a regular letter may take several days or even weeks to reach the recipient.

Currently, the Internet uses almost all known communication lines from low-speed telephone lines to high-speed digital satellite channels.

In fact, the Internet consists of many local and global networks belonging to various companies and enterprises, interconnected by various communication lines. The Internet can be imagined as a mosaic made up of small networks of different sizes that actively interact with each other, sending files, messages, etc.

Like any other network on the Internet, there are 7 levels of interaction between computers: physical, logical, network, transport, session level, presentation and application level. Accordingly, each level of interaction corresponds to a set of protocols (i.e., rules of interaction).

Physical layer protocols determine the type and characteristics of communication lines between computers. The Internet uses almost all currently known communication methods, from a simple wire (twisted pair) to fiber-optic communication lines (FOCL).

For each type of communication line, a corresponding logical level protocol has been developed to control the transmission of information over the channel. Logical layer protocols for telephone lines include SLIP (Serial Line Interface Protocol) and PPP (Point to Point Protocol).

For communication over a cable local network, these are packet drivers for LAN cards.

Network layer protocols are responsible for transmitting data between devices on different networks, that is, they are responsible for routing packets in the network. Network layer protocols include IP (Internet Protocol) and ARP (Address Resolution Protocol).

Transport layer protocols control the transfer of data from one program to another. Transport layer protocols include TCP (Transmission Control Protocol) and UDP (User Datagram Protocol).

Session-level protocols are responsible for establishing, maintaining and destroying the corresponding channels. On the Internet, this is done by the already mentioned TCP and UDP protocols, as well as the UUCP (Unix to Unix Copy Protocol).

Representative layer protocols are responsible for serving application programs. Executive-level programs include programs that run, for example, on a Unix server to provide various services to subscribers. These programs include: telnet server, FTP server, Gopher server, NFS server, NNTP (Net News Transfer Protocol), SMTP (Simple Mail Transfer Protocol), POP2 and POP3 (Post Office Protocol), etc.

Application layer protocols include network services and programs for providing them.

The Internet is a constantly developing network, which still has everything ahead, let’s hope that our country will not lag behind the progress.

/>/>/>/>/>/>/>/>/>/>/>/>Conclusion

A computer network is an association of several computers for the joint solution of information, computing, educational and other problems.

The main purpose of computer networks is to share resources and implement interactive communication both within one company and

and beyond.

A local computer network is a collection of computers connected by communication lines, providing network users with the potential opportunity to share the resources of all computers. On the other hand, simply put, a computer network is a collection of computers and various devices that provide information exchange between computers on the network without the use of any intermediate storage media.

A global computer network (WAN or WAN - World Area NetWork) is a network connecting computers that are geographically distant at large distances from each other. It differs from a local network in more extensive communications (satellite, cable, etc.). The global network connects local networks.

Internet is a global computer network covering the whole world.

In fact, the Internet consists of many local and global networks belonging to various companies and enterprises, interconnected by various communication lines.

List of used literature

1. “Internet at your home”, S. V. Simonovich, V. I. Murakhovsky, LLC “AST-Press Book”, Moscow 2002.

2. Gerasimenko V.G., Nesterovsky I.P., Pentyukhov V.V. and others. Computer networks and means of their protection: Textbook / Gerasimenko V.G., Nesterovsky I.P., Pentyukhov V.V. etc. – Voronezh: VSTU, 1998. – 124 p.

3. ComputerWeek Moscow, a weekly magazine for entrepreneurs and specialists in the field of information technology.

4. Magazine for personal computer users PC World.

5. Kamalyan A.K., Kulev S.A., Nazarenko K.N. and others. Computer networks and information security tools: Textbook / Kamalyan A.K., Kulev S.A., Nazarenko K.N. and others - Voronezh: VSAU, 2003.-119p.

6. Kurnosov A.P. Workshop on computer science/Ed. Kurnosova A.P. Voronezh: VSAU, 2001.- 173 p.

7. Malyshev R.A. Local computer networks: Textbook / RGATA. – Rybinsk, 2005. – 83 p.

8. Olifer V.G., Olifer N.A. Network operating systems/ V.G. Olifer, N.A. Olifer. – St. Petersburg: Peter, 2002. – 544 p.: ill.

9. Olifer V.G., Olifer N.A. Computer networks. Principles, technologies, protocols/V.G. Olifer, N.A. Olifer. - St. Petersburg: Peter, 2002.- 672 p.: ill.

10. Simonovich S.V. Informatics. Basic course/Simonovich S.V. and others - St. Petersburg: Peter Publishing House, 2000. - 640 pp.: ill.

3. Software

Topology- physical or electrical configuration of cabling and network connections.
Topology is the skeleton of the network.
There are several main types

The choice of topology used depends on your conditions, tasks and capabilities. Or it is determined by the standard of the network used.
You can connect your computers and other devices in any way most suitable for you, but in this case you will have to use a very specific standard that supports this topology.
If it is convenient for you, you can even connect some computers to a network with one topology, and some to a network with a different topology, then connect the networks to each other using some other method.

Common bus

All computers are connected to one cable (data bus). At the ends of the cable are installed terminators . Their presence is mandatory for Ethernet networks. 10 Megabit networks are built using this topology 10Base-2 And 10Base-5 . Used as a cable coaxial cable . Damage to the common cable or any of the two terminators leads to failure of the network section between these terminators (network segment). Disabling any of the connected devices does not have any effect on the network.

For a 10Base-2 network this will look like

which is absolutely the same from a topological point of view, but may turn out to be more convenient when laying.
In 100Mbit networks this topology is not used, but is used " Star".

Each computer (etc.) is connected by a separate wire to a separate port on a device called a hub or repeater (repeater) or hub (Hub).

Concentrators can be either active or (theoretically) passive. If the connection between the device and the hub is lost, the rest of the network continues to work. True, if this device was the only server, then the work will be somewhat difficult. If the hub fails, the network will stop working.
This network topology is most convenient when searching for damage to network elements: cables, network adapters or connectors. When adding new devices, a star is also more convenient than a shared bus topology. You can also take into account that 100 and 1000 Mbit networks are built using a “Star” topology.

The Ethernet standard was developed in the 70s at the PARC research center of XEROX Corporation.
Some works note that "Ethernet" is a trademark registered by XEROX.
It was then further developed jointly by DEC, Intel and XEROX (hence the abbreviation DIX) and first published as the "Blue Book Standard" for Ethernet1 in 1980. This standard was further developed and in 1985 a new one was released - Ethernet2 (also known as DIX).

IEEE 802.3 was approved in 1985 for standardization by the IEEE (Institute of Electrical and Electronics Engineers) LAN Committee and was published under the title: "IEEE 802.3 Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications."
This standard establishes general rules for data transmission in local networks.

Ethernet and IEEE802.3 describe similar technologies. Both are CSMA/CD LANs. Both technologies are broadcast technologies. In other words, all stations see all frames, even if they are not intended for that station. Each station must check the received frame to determine whether it is the destination. If so, then the frame is passed to a higher-level protocol for appropriate processing.

The difference between Ethernet and IEEE 802.3 is minor.

Both Ethernet and IEEE 802.3 are built into the hardware.

IEEE 802.3 defines several different physical layers, while Ethernet defines one.

Each IEEE 802.3 physical layer has a name that reflects its characteristics.
For example: 10Base5
10 - local network speed in Megabits per second
Base = baseband or Broad = broadband
5 - segment length in hundreds of meters (in this case 500)

Physical characteristics of the two standards

Unshielded twisted-pairwire (UTP) - unshielded twisted pair
Ethernet is closest to 10Base5.

10Base2 or Thin Ethernet

10 Base-T or Ethernet over twisted pair

To connect devices, the 10 Base-T standard provides for the use of a wire having two pairs: one for transmission, the other for reception.
There are two possible cable layouts in the port. MDI for DTE (Data Terminal Equipment) devices (computers, printers, etc.) and MDI-X for hubs.

When connecting an MDI port to an MDI-X port, direct cabling is used. And when connecting the same ports MDI and MDI or MDI-X and MDI-X, “inverted” (crossover) cable routing is used. In this case, “transmission” is correspondingly connected to “reception”.

Repeaters

Ethernet networks can be extended using a device called a repeater. An Ethernet repeater is a device physically located on a network with two or more Ethernet ports. These ports can be any type: AUI, BNC, RJ-45 or fiber-optic, or any combination.
The main function of the repeater is to receive data on one of the ports and immediately forward it to other ports. The data (signal) is re-formed during transmission to other ports to eliminate any deviations that could arise during the movement of the signal from the source.
Repeaters can also perform a function called "separation". If the repeater detects a large number of collisions occurring on one of the ports, it concludes that there was a failure somewhere on that segment and isolates it from the rest of the network. This feature was made to prevent errors from one segment from propagating throughout the entire network.

Repeaters have a negative feature in that it introduces a delay in the propagation of the signal through the network. All Ethernet networks use an access protocol called CSMA/CD ("Carrier Sense Multiple Access, with Collision Detection").
For this protocol to work properly, it needs to be able to detect when a collision has occurred. CSMA/CD determines this occurrence by comparing the data that is on the network with what should have been sent to the network. If any difference is detected, it means that a collision has occurred (simultaneous transmission by two devices) and the transmission is stopped immediately. CSMA/CD then waits a random amount of time and retries the transmission.
There is a flaw in CSMA/CD that limits the size of the network. The sent bits do not instantly reach all points on the network; a certain short period of time is required for the signal to travel through the wires and through each repeater on the network. This time can be measured and is called the "Propagation Delay". If the "propagation delay" between the signal source and the most distant network source is greater than half the size of the smallest frame that can exist, then CSMA/CD will not be able to correctly detect the collision, and data on the network may be lost or corrupted.

IEEE 10Base5 or thick Ethernet is the oldest standard among the others. Currently (1998) it is difficult to find new equipment for sale for building a network based on this standard. Its main parameters

When connecting, a 15 pin connector (AUI) is used

Transceivers

The name "Transceiver" comes from the English words transmiter and receiver.
The transceiver allows a station to transmit to and receive from a common network transmission medium. Additionally,
Ethernet transceivers detect collisions in the medium and provide electrical isolation between stations.
10Base2 and 10Base5 transceivers connect directly to the transmission medium (cable) common bus. While the first standard typically uses an internal transceiver built into the controller circuit and a T-connector to connect to the cable, the second (10Base5) uses a separate external transceiver and an AUI cable or transceiver cable to connect to the controller. 10BaseF, 10BaseT, FOIRL also usually use internal transceivers.
It must be said that there are also external transceivers for 10Base2, 10BaseF, 10baseT and FOIRL, which are connected to the AUI port either directly or via an AUI cable.

Example of an external transceiver for 10Base2:

AUI connector
Attachment Unit interface

100 Base-TX

Currently, 100Base-TX networks are the most accessible 100Mbit networks. There are also 100VG and 100Base-T4 networks. But they “didn’t catch on.”

To combine 10 and 100 Mbit networks, 10/100 Mbit hubs, switches or routers are mainly used.

1000Base-T

The network will use twisted pair cable category 5 or better, 4 pairs (8 wires) at a frequency of 125 MHz. The maximum distance between devices is 100 meters.

1.3 Required equipment

1.3.1 Thin Ethernet 10Base2

Coaxial cable

Coaxial cable (from Latin co- together and axis- axis), consists of two coaxial flexible metal cylinders separated by a dielectric.

Characteristics of coaxial cables

Notes: PE - polyethylene, S-PE - polyethylene foam, M - copper wire,
ML - tinned copper wire, STM - steel-copper wire,
MS - silver-plated copper wire

Thin Ethernet connectors

Terminator

This is a connector (male) with a resistor sealed in it, between the central and external contacts. The resistance of the resistor must be equal to the characteristic impedance of the cable. For networks such as 10Base-2 or thin Ethernet, this value is 50 ohms. Only one terminator in a 10Base2 segment can be grounded. For grounding, a terminator with a chain and a contact at its end is used. For 10Base5, grounding one and only one of the terminators (more precisely, one of the segment points) is mandatory.

Designed to connect devices to a network segment based on 10 Base-2 (thin Ethernet).

When disconnecting the device, the T-connector must be left in the network so as not to disrupt its functionality. Or replace the T-connector with a straight connector (I-connector).

Transitionsstraight
barrel-connector/I-connector, bulk-head connector

Designed to connect the mating parts of two connectors with the same or different connecting dimensions, when their direct mechanical connection is not feasible or direct electrical connection is undesirable.

Used to connect two pieces of coaxial cable with connectors located at the ends. And also for organizing the supply of coaxial cable to the workplace, in order to avoid accidental breakage or unwanted bending of the main wire.

You can also use a T connector to connect two pieces of coaxial cable.

1.3.2 Twisted Pair 10BaseT

Unshielded Twisted Pair
UTP

“Twisted Pair” cable consists of “pairs” of wires twisted around each other and at the same time twisted around other pairs, within one sheath. Each pair consists of a wire called "Ring" and a wire called "Tip". (The names come from telephony). Each pair in the sheath has its own number, so each wire can be identified as Ring1, Tip1, Ring2, Tip2, ....
In addition to the wire numbering, each pair has its own unique color scheme.
Blue/White for 1st pair,
orange/white - for 2nd,
green/white - for 3rd
brown/white - for 4th
and so on 25 pairs.
For each pair of wires, the Ring wire is painted in the primary color with additional stripes, and the Tip wire is the opposite. For example, for pair 1, Ring1 wire will be blue with white stripes, and Tip1 wire will be white with blue stripes.
In practice, when the number of pairs is small (4 pairs), coloring the main wire with stripes of an additional color is often not used.
In this case, the wires are colored in pairs:
Blue and white with blue stripes
Orange and white with orange stripes
Green and white with green stripes
Brown and white with brown stripes.

To indicate the diameter of a wire, an American measure is often used - AWG (American Wire Gauge) (gauge-gauge, diameter). Normal wire for use in 10 Base-T is 22 or 24 AWG. Moreover, the smaller the diameter of the wire, the greater this value.
According to standards, wire is divided into several categories according to its “throughput”.

Usually it is written on the wire which category it belongs to. For example: "...CATEGORY 5 UTP..."
International standard ISO/IEC 11801 - equivalent to EIA/TIA-568.

Twisted pair connectors

Twisted pair networks include 10BaseT, 100BaseTX, 100BaseT4 networks, and the adoption of the 1000BaseT standard is also very likely.
In network cards of computers, in hubs and on walls there are sockets (jacks), plugs are stuck into them.

Twisted pair connectors

Eight Pin Modular Connector (Plug)

Common name "RJ-45"

Fork with insert

State budgetary professional educational institution “Arzamas Instrument-Making College named after P.I. Plandina"

I approve

Director of the State Budgetary Educational Institution

"APK im. P. I. Plandina"

___________/S.A. Ermolaev/

WORK PROGRAM OF TRAINING PRACTICE

PM 02. Organization of network administration

UP.02.01

specialty 02/09/02

Computer networks

Arzamas, 2016

The work program of educational practice was developed on the basis of the Federal State Educational Standard for the specialty of secondary vocational education02/09/02. “Computer networks”, Regulations on the practice of students mastering basic professional educational programs of secondary vocational education, approved by Order of the Ministry of Education and Science of the Russian Federation dated April 18, 2013 No. 291.

Organization-developer: GBPOU "APK im. P.I.Plandina"

Developers: Malova E.V., teacher at the State Budgetary Educational Institution “Agroindustrial Complex named after. P.I. Plandina."

Approved by the Methodological Council of the State Budgetary Educational Institution “Agroindustrial Complex named after. P.I. Plandina"

CONTENT

2

RESULTS OF MASTERING TRAINING PRACTICE……

3

STRUCTURE AND CONTENT OF EDUCATIONAL PRACTICE...

4

CONDITIONS FOR IMPLEMENTING EDUCATIONAL PRACTICE……..

5

CONTROL AND EVALUATION OF THE RESULTS OF TRAINING PRACTICE ……………………………………………………...

1. PASSPORT OF THE WORKING PROGRAM OF TRAINING PRACTICE

1.1. Scope of application

The work program of educational practice is part of the training program for mid-level specialists (hereinafter referred to as PPSSZ) in accordance with the Federal State Educational Standard for Secondary Professional Education in the specialty02/09/02 Computer networks, in terms of mastering the main types of professional activities (hereinafter - VPA).

1.2 Goals and objectives of educational practice

The purpose of educational practice is the formation of skills in students, the acquisition of initial practical experience within the professional modules of the PPSSZ in the main types of professional activities for their subsequent development of general and professional competencies in their chosen specialty.

The objectives of educational practice are:

Development by each student of an appropriate, necessary and sufficient set of practical skills important for the subsequent development of competencies;

Fostering a student’s conscious understanding and self-assessment of their own activities.

Requirements for the results of mastering educational practice.

As a result of undergoing practical training in types of professional activity, the student must have initial practical experience and have the skills:

Organization of software maintenance and operation of software for workstations and computer network servers

Organization of software maintenance and operation of active and passive computer network equipment

Practical experience in software maintenance and operation of workstations, active and passive equipment and related computer network software

configure local network in Windows 7;

Windows;

1.3. Number of hours for mastering the work program of educational practice:

Name of professional module

Total hours

Distribution of hours by semester

Educational practice on computer network software

Total

2. RESULTS OF MASTERING THE WORK PROGRAM OF TRAINING PRACTICE

The result of mastering the work program of educational practice is the mastery by students of professional (PC) and general (GC) competencies in their chosen specialty.

Understand the essence and social significance of your future profession, show sustained interest in it

OK 2

Organize your own activities, choose standard methods and methods of performing professional tasks, evaluate their effectiveness and quality

OK 3

Make decisions in standard and non-standard situations and take responsibility for them

OK 4

Search and use information necessary for the effective performance of professional tasks, professional and personal development

OK 5

Use information and communication technologies in professional activities

OK 6

Work collaboratively and in a team, communicate effectively with colleagues, management, and consumers

OK 7

Take responsibility for the work of team members (subordinates) and for the results of completing tasks

OK 8

Independently determine the tasks of professional and personal development, engage in self-education, consciously plan professional development

OK 9

To navigate the conditions of frequent changes in technology in professional activities

3. THEMATIC PLAN AND CONTENT OF TRAINING PRACTICE

3.1. Thematic plan and content of educational practice

professional

modules and themes

educational practice

Volume

hours

Mastery level

Educational practice on computer network software

Types of work:

Organization of software maintenance and operation of workstations and office equipment of a computer network

Organization of software maintenance and operation of software for workstations and computer network servers

Organization of software maintenance and operation of active and passive computer network equipment

Installation and configuration of application software for workstations and servers. Performing data backup and recovery. Diagnosing performance, troubleshooting problems and failures of the operating system and application software. Installing, updating and uninstalling versions of personal computer operating systems. Performing administration of operating systems; updating and uninstalling the application software version of personal computers. Updating and removing device drivers for personal computers, peripheral devices and equipment. Updating the firmware of computer components, servers, peripheral devices and equipment.

1. Installing a WEB server

2. WEB server installation

3. WEB server installation

4. Configuring the web server

5. Configuring the web server

6. Configuring the web server

7. Interaction with databases.

8. Interaction with databases.

9. Interaction with databases.

10.Installing and configuring drivers

11.Installation of software: MS Office, specialized programs and workstations.

12.Use of file manager FAR/and other alternative programs.

13.Disk maintenance (defragmentation, cleaning, error checking, file recovery)

14.Installation and configuration of the Kaspersky anti-virus program.

15. Network analysis and monitoring.

16. Installation and configuration of browsers Opera, Mozilla, Google Chrome, Internet E xplorer

17.Installation and configuration of mail utilities Microsoft OutLook, OutLook Express.

18.Using the FTP service using a browser.

19.Setting up and using an FTP client

20. Installation of specialized programs and automated workstations.

21.Organization of uninterrupted operation of the system for backup and recovery of information

22.Updating and removing versions of personal computer operating systems.

23.Administering operating systems.

24. Updating and removing device drivers for personal computers.

25. Updating and removing peripheral device drivers.

26. Updating and removing peripheral device drivers.

27. Updating and removing hardware drivers.

28. Updating the firmware of computer components.

29. Firmware update for server components.

30. Firmware update for peripheral components.

31. Firmware update for hardware components.

32.Working with BIOS.Main sections of BIOS.Overclocking a computer using BIOS

33. BIOS update procedure

34. BIOS diagnostic tools

35.Installation of KS software.Operation of the CS software

36.. Differentiated credit

Interim certification in the form of differential credit

4. CONDITIONS FOR IMPLEMENTING THE WORK PROGRAM OF TRAINING PRACTICE

4.1. Minimum logistics requirements

The implementation of the work program of educational practice presupposes the presence

1.Equipment:

PC, software, individual components, peripheral equipment (microphones, speakers), office equipment (printers, scanners)

2. Tools and accessories:

Computers – 24.

3. Teaching aids:

Electronic reference book "PC"

4.3. General requirements for the organization of the educational process.

Training practice is carried out by industrial training masters and/or professional cycle teachers. Sold in a concentrated manner.

4.4. Personnel support of the educational process.

Industrial training masters, teachers

4.5 Information support for educational practice

Main sources:

1. Kelim Yu.M. Computer technology: a textbook for students of secondary vocational education institutions. – M.: publishing center “Academy”, 2014. – 368 p. (electronic version)

   Maksimov N.V. Architecture of computers and computing systems. M.: FORUM-INFRA-M, 2013

   Tanenbaum E. Computer architecture. St. Petersburg: Peter, 2013

Additional sources:

1. Kuzin A.V. Architecture of computers and computing systems. M.: FORUM-INFRA-M, 2006

Electronic versions of textbooks:

1. Ilyukhin B.V. Computer hardware and networks. Tomsk: Tomsk interuniversity. distance center Education, 2005

   Kolesnichenko O.V. Architecture of RS tools. St. Petersburg: BHV-Petersburg, 2010

   Stepanov A.N. Architecture of computer systems and computer networks. St. Petersburg: Peter, 2007

Internet resources:

EOR: electronic reference book "PC"

http://nn.nix.ru/

http://pusk.at.ua/publ/1-1-0-2

4. 6 Requirements for organizing certification and evaluating the results of educational practice

Certification of educational practice is carried outin the form of differentiated credit on the last day of educational practice on the basis of equipped college classrooms.

Students who have completed the educational practice program in full and have submitted a diary and report of the educational practice are allowed to undergo certification.

During the certification process, an examination is carried out of the formation of practical skills and the acquisition of initial practical work experience in terms of mastering the main type of professional activity, mastering general and professional competencies.

The grade for educational practice is determined taking into account:

meeting deadlines and submitting reports for each day of practice,

compliance with labor protection issues, safety regulations and fire safety,

provided that each day's tasks are completed in full,

demonstration of acquired skills,

explanations of algorithms of actions when performing acquired skills.

demonstrating the ability to search and select the necessary information on the global network on specialized resources and the ability to apply it when demonstrating practical skills;

Demonstrating the ability to work in a team and individually.

5. CONTROL AND EVALUATION OF THE RESULTS OF MASTERING THE TRAINING PRACTICE PROGRAM

Monitoring and evaluation of the results of mastering educational practice is carried out by the practice manager in the process of conducting training sessions, students’ independent completion of assignments, and performing practical tests. As a result of mastering educational practice within the framework of professional modules, students undergo intermediate certification in the formcredit/differential credit.

Expert assessment of the completed written report for each day

Expert assessment of report security for each day

Practical experience gained:

operation of computer network workstations.

Acquired skills:

choose the software configuration of a personal computer, server and peripheral equipment that is optimal for solving user problems;

ensure compatibility of components of personal computers and servers, peripheral devices and equipment;

configure software operating parameters;

diagnose software performance;

troubleshoot software problems and malfunctions;

select the software configuration of a personal computer or server that is optimal for the requirements and tasks solved by the user;

install and administer operating systems on personal computers and servers, as well as configure the user interface;

evaluate the performance of a computer system;

optimize the operation of a personal computer (workstations);

manage data files on local, removable storage devices, as well as on local computer network drives and on the Internet;

navigate Internet web resources using a web browser program;

search, sort and analyze information using Internet search sites;

network user support;

configure local network inWindows 7;

configure Internet access from a local network;

connect and configure a network printer in the OSWindows;

analyze network traffic using network monitor

Computer networks. Classification of computer networks. ……………4

Fast Ethernet network. …………………………………………………………..5

Network topology. ……………………………………………………...….8

Ensuring work safety in the Computer Center. ……….12

Computer networks. Classification of computer networks.

According to the principles of construction, computer networks are divided into local and remote (Figure 1).

Local networks are created, as a rule, in one organization or in one room.

The simplest version of such a network is to connect computers through parallel or serial ports. In this case, there is no need for any additional equipment. There should only be connecting conductors. This connection between computers is configured within the same room. It is used to transfer data from one computer to another. In this case, you can transfer data without using floppy disks. Any modern operating system shell has software that ensures such data transfer.

In local peer-to-peer computer networks, computers connect to the network through special network adapters, and the functioning of the network is supported by the network operating system. Examples of such operating systems are: Novell Personal Net Ware, Net Ware Line, Windows for Workgroups.

All computers and their operating systems in local peer-to-peer computer networks must be of the same type. Users of this network can transfer data to each other, use shared printers, magnetic and optical disks, etc.

In a local multi-rank computer network, one more powerful computer is used, which is called a server, and other, less powerful ones are called workstations. Servers use special system software that differs from workstation system software.

Remote computer networks are divided into regional and international. Regional ones are created in certain regions, for example, a state, and international ones ensure the connection of your computer with another computer on the World Wide Web. An example of such networks is Relcom (for CIS countries) and Internet (for the whole world). In principle, it is possible to access the Internet from regional computer networks.

Communication between computers in regional networks is provided by regular telephone networks or specially dedicated networks through special devices called modems. The modem converts binary code signals into language range audio signals, and vice versa.

Computers in a given area (city) are connected via modems and communication lines to a more powerful computer called a provider. There are currently more than 100 providers operating in Ukraine.

Each computer user that is connected to the network is assigned details (address). Providers, using the details, ensure communication between the corresponding user computers.

Communication between computers on different continents is carried out via satellite communication channels.

A report on your requirements on the topic “Computer networks. Classification of computer networks” can be ordered from the Diplomtime company.

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