Effective use of IP is impossible without the use of network technologies. A computer network is a collection workstations(for example, based on personal computers), interconnected data transmission channels, through which circulate messages. Network operations are governed by a set of rules and conventions - network protocol, which defines the technical parameters of the equipment required for joint work, signals, message formats, methods for detecting and correcting errors, algorithms for the operation of network interfaces, etc.

Local networks allow efficient use of such system resources as databases, peripheral devices such as laser printers, high-speed magnetic disk drives of large volume, etc., as well as using e-mail.

Global networks appeared when a protocol was created that allows you to connect local networks with each other. This event is usually associated with the emergence of a pair of interconnected protocols - the transmission control protocol / Internetwork protocol TCP / IP (transmission control Protocol/ Internet Protocol), which on January 1, 1983 linked the ARPANET network and the US defense information network into a single system. Thus was created the "network of networks" - the Internet. Other important event in the history of the Internet was the creation of a distributed hypertext information system WWW (from English, World Wide web - "The World Wide Web"). It became possible due to the development of a set of rules and requirements that make it easier to write software for workstations and servers. And, finally, the third important event in the history of the Internet was the development of special programs that facilitate the search for information and process text documents, images and sounds.

The Internet network consists of computers that are its permanent nodes (they are called host from English. host- owner) and terminals, that connect to the host. The hosts are connected to each other via the Internet protocol, and any personal computer can be used as a terminal by running a special emulator program. Such a program allows him to “pretend” to be a terminal, that is, to accept commands and send the same response signals as a real terminal. In order to solve the problem of accounting for millions of PCs connected to a single network, the Internet uses unique codes - a number and a name that are assigned to each computer. Country names are used as part of the name (Russia - RU, Great Britain - UK, France - FR), and in the USA - types of organizations (commercial - COM, education system EDU, network services - NET).

In order to connect to the network via the Internet Protocol, you must agree with the provider organization (from the English. provider - provider), which will redirect information using the TCP / IP network protocol over telephone lines to this computer through a special device - modem. Usually, Internet providers, when registering a new subscriber, give him a specially written software package that automatically installs the necessary network software on the subscriber's computer.

The Internet provides users with many different resources. From the point of view of using the Internet for educational purposes, two are of greatest interest - the system of file archives and the World Wide Web database (WWW, "World Wide Web"),

File archive system becomes available via FTP protocol { File Transfer Protocol - file transfer protocol); this archive system is called FTP archives. FTP archives are a distributed depository of various data accumulated over 10-15 years. Any user can anonymously access this repository and copy the materials of interest to him. The FTP protocol commands define the parameters of the data transfer channel and the transfer process itself, as well as the nature of the work with the file system. The FTP protocol allows users to copy files from one network-attached computer to another. Another tool, the Telnet machine access protocol, allows you to connect to another terminal in the same way as you connect by telephone to another subscriber, and to work with him jointly.

A feature of the WWW distributed hypertext information system is the use of hypertext links, which make it possible to view materials in the order they are selected by the user.

The WWW is built on four cornerstones:

    hypertext markup language for HTML documents;

    universal way of URL addressing;

    HTTP hypertext message delivery protocol;

    generic CGI gateway.

The standard storage object in a database is an HTML document, which corresponds to a plain text file. Customer requests are served by a program called HTTP-server. It implements HTTP communication { hypertext Transfer Protocol - Hypertext Transfer Protocol), which is an add-on over TCP / IP - the standard protocol of the Internet. The completed information object, which is displayed by the program by the user's client when accessing the information resource, is page www databases,

The location of each resource is determined unifiedresource pointerURL(from English. Uniform resource locator). A standard URL consists of four parts: the transfer format (access protocol type), the name of the host where the requested resource is located, the path to this file, and the file name. Using the URL naming system, links in hypertext describe the location of a document. Communication with all network resources is carried out through a single user interface CUI (Common user Interface). The main purpose of this tool is to provide a uniform flow of data between the server and the application program that runs under its control. Viewing an information resource is carried out using special programs - browsers(from English. browse - read, skim).

The term "browser" does not refer to all Internet resources, but only to that part of them, which is called the "World Wide Web". Only here the HTTP protocol is used, which is necessary for transferring documents written using the HTML language, and the browser is a program that recognizes the HTML codes for formatting the transferred document and displays it on the computer screen in the form that the author intended, in other words, the program viewing an HTML document.

To date, a large number of browser programs for the Internet have been developed. Among them are Netscape Navigator, MS Internet Explorer, Mosaic, Tango, Ariadna, Cello, Lynx.

Let's dwell on how viewers (browsers) work.

Data processing in HTTP consists of four stages: opening a connection, forwarding a request message, forwarding response data, and closing a link.

To open a connection, the World Wide Web browser connects to the HTTP server (Web server) specified in the URL. After the connection is established, the WWW browser sends a request message. It tells the server which document is needed. After processing the request, the HTTP server sends the requested data to the WWW server. All these actions are visible on the monitor screen - all this is done by the browser. The user sees only the main function, which is the indication, that is, the selection of hyperlinks from the general text. This is achieved by changing the pattern of the mouse pointer: when the pointer hits a hyperlink, it rotates from the "arrow" to the "pointing finger" - a hand with an outstretched index finger. If you click the mouse button at this moment, the browser will "leave" the address indicated in the hyperlink.

The HTTP server technology is so simple and cheap that there are no restrictions for creating a WWW-like system within a single organization. Since it is only necessary to have an internal local area network with TCP / IP protocol, it is possible to create a small (compared to global) hypertext "Web". This technology for creating Internet-like local area networks is called the Intranet.

At present, more than 30 terabits of information (that's about 30 million books of 700 pages each) move monthly on the Internet, and the number of users, according to various estimates, is from 30 to 60 million people.

  • Foreword
  • Chapter 1.
    Historical prerequisites for the development of high-speed data networks
  • Chapter 2
    Reference model of interaction of open systems EMBOS (Open System Interconnection - OSI model)
  • Chapter 3
    International Standards Organizations
  • Chapter 4
    Physical and logical data encoding
  • Chapter 5
    Narrowband and broadband systems. Data Multiplexing
  • Chapter 6
    Data transfer modes. Transmission media
  • Chapter 7
    Structured cabling systems
  • Chapter 8
    Topologies of data transmission systems
  • Chapter 9
    Channel access methods
  • Chapter 10
    Switching technologies
  • Chapter 11
    Communication of network segments
  • Literature

Chapter 5. Narrowband and broadband systems. Data Multiplexing

A narrowband system (baseband) uses a digital signal transmission method. Although a digital signal has a wide spectrum and theoretically occupies an infinite bandwidth, in practice the bandwidth of the transmitted signal is determined by the frequencies of its fundamental harmonics. They make the main energy contribution to signal formation. In a narrowband system, transmission is carried out in the original frequency band, there is no transfer of the signal spectrum to other frequency regions. It is in this sense that the system is called narrowband. The signal occupies almost the entire bandwidth of the line. To regenerate the signal and amplify it in data networks, special devices are used - repeaters (repeater, repeater).

An example of the implementation of narrowband transmission are local area networks and the corresponding IEEE specifications (for example, 802.3 or 802.5).

Previously, narrowband transmission due to signal attenuation was used at distances of the order of 1-2 km over coaxial cables, but in modern systems, thanks to various types of coding and multiplexing of signals and types of cable systems, the restrictions have been pushed back to 40 kilometers or more.

The term broadband (broadband) transmission was originally used in telephone communication systems, where it denoted an analog channel with a frequency range (bandwidth) of more than 4 kHz. In order to save resources when transmitting a large number of telephone signals with a frequency band of 0.3-3.4 kHz, various schemes for compacting (multiplexing) these signals have been developed to ensure their transmission over a single cable.

In high-speed network applications, broadband transmission means that instead of a pulse, an analog carrier is used for data transmission. By analogy, the term broadband internet' means you are using a bandwidth greater than 128 Kbps (Europe) or 200 Kbps (USA). The broadband system has a high bandwidth, provides high-speed data and multimedia information (voice, video, data). Examples are ATM networks, B-ISDN, Frame Relay, CATV cable broadcasting networks.

The term "multiplexing" is used in computer technology in many ways. By this we mean the combination of several communication channels in one data transmission channel.

We list the main multiplexing techniques: frequency multiplexing - Frequency Division Multiplexing (FDM), time multiplexing - Time Division Multiplexing (TDM) and spectral or wavelength multiplexing (wave) - Wavelength Division Multiplexing (WDM).

WDM is used only in fiber optic systems. Cable TV, for example, uses FDM.

FDM

In frequency multiplexing, each channel is assigned its own analog carrier. In this case, any type of modulation or a combination of them can be used in FDM. For example, in cable television, a coaxial cable with a bandwidth of 500 MHz provides transmission of 80 channels of 6 MHz each. Each of these channels is in turn obtained by multiplexing subchannels for audio and video transmission.

TDM

With this type of multiplexing, low-speed channels are combined (merged) into one high-speed one, through which a mixed data stream is transmitted, formed as a result of aggregation of the original streams. Each low-speed channel is assigned its own time slot (length of time) within a cycle of a certain duration. Data is represented as bits, bytes, or blocks of bits or bytes. For example, channel A is assigned the first 10 bits within a time interval of a given duration (frame, frame), channel B is assigned the next 10 bits, etc. In addition to data bits, the frame includes service bits for transmission synchronization and other purposes. A frame has a strictly defined length, which is usually expressed in bits (for example, 193 bits) and a structure.

Network devices that multiplex data streams of low-speed channels (tributary, component streams) into a common aggregated stream (aggregate) for transmission over one physical channel are called multiplexers (multiplexer, mux, mux). Devices that divide the aggregated stream into component streams are called demultiplexers.

Synchronous multiplexers use a fixed time slot division. The data belonging to a particular component stream has the same length and is transmitted in the same time slot in each frame of the multiplexed channel. If information is not transmitted from some device, then its time slot remains empty. Stat muxes solve this problem by dynamically assigning a free timeslot to the active device.

WDM

WDM uses different wavelengths of light signal to organize each channel. In fact, this is a special kind of frequency multiplexing at very high frequencies. With this type of multiplexing, the transmitters operate at different wavelengths (for example, 820nm and 1300nm). The beams are then combined and transmitted over a single fiber optic cable. The receiving device separates the transmission by wavelength and directs the beams to different receivers. To merge / separate channels by wavelength, special devices are used - couplers (coupler). The following is an example of such multiplexing.

Fig.5.1. WDM multiplexing

Among the main designs of couplers, a distinction is made between reflective couplers and centrally symmetrical reflective couplers (SCRs). Reflective couplers are tiny pieces of glass “twisted” in the center in the form of a star. The number of output beams corresponds to the number of coupler ports. And the number of ports determines the number of devices that transmit at different wavelengths. Two types of reflective couplers are shown below.

Fig.5.2. transmitting star

Fig.5.3. reflective star

The centrally symmetrical reflective coupler uses the reflection of light from a spherical mirror. In this case, the incoming beam is divided into two beams symmetrically to the center of the bending of the mirror sphere. When the mirror is rotated, the position of the sphere's bend changes and, accordingly, the path of the reflected beam changes. You can add a third fiber optic cable (fiber) and redirect the reflected beam to one more port. The implementation of WDM - multiplexers and fiber optic switches is based on this idea.

Fig.5.4. Centrally symmetrical reflective coupler

Optical multiplexers can be implemented not only with CSR couplers, but also with reflective filters and diffraction gratings. They are not covered in this tutorial.

The main factors that determine the possibilities of various implementations are interfering crosstalk and channel separation. The amount of crosstalk determines how well the channels are separated, and, for example, shows how much of the power of the 820-nm beam was on the 1300-nm port. A pickup of 20 dB means that 1% of the signal appeared on the wrong port. To ensure reliable separation of signals, the wavelengths must be spaced “widely”. It is difficult to recognize close wavelengths, such as 1290 and 1310 nm. Usually 4 multiplexing schemes are used: 850/1300, 1300/1550, 1480/1550 and 985/1550 nm. Best Features while they have CSR-couplers with a system of mirrors, for example, two (Fig. 5.5).

Fig.5.5. SCR coupler with two mirrors

WDM, which is one of the three varieties of WDM, occupies a middle position in terms of spectrum efficiency. In WDM systems, spectral channels are combined, the wavelengths of which differ from one another by 10 nm. The most productive technology is DWDM (Dense WDM). It provides for the combination of channels spaced apart in the spectrum by no more than 1 nm, and in some systems even by 0.1 nm. Due to this dense signal distribution over the spectrum, the cost of DWDM equipment is usually very high. Spectral resources are used least efficiently in new systems based on CWDM technology (Coarse WDM, sparse WDM systems). Here, the spectral channels are separated by at least 20 nm (in some cases, this value reaches 35 nm). CWDM systems are typically used in metropolitan area networks and LANs where low equipment cost is an important factor and 8-16 WDM channels are required. CWDM equipment is not limited to one part of the spectrum and can operate in the range from 1300 to 1600 nm, while DWDM equipment is tied to a narrower range of 1530 - 1565 nm.

conclusions

A narrowband system is a transmission system in the original frequency band using digital signals. To transmit several narrowband channels in one broadband channel, modern transmission systems over copper cables use TDM time multiplexing. Fiber optic systems use WDM wave multiplexing.

Additional Information

Control questions

  • The device, in which all incoming information flows are combined in one output interface, performs the following functions:
    • switch
    • repeater
    • multiplexer
    • demultiplexer
  • Ten signals, each requiring 4000 Hz bandwidth, are multiplexed into one channel using FDM. What should be the minimum bandwidth of the multiplexed channel with a guard interval width of 400 Hz?
    • 40800 Hz
    • 44000 Hz
    • 4800 Hz
    • 43600 Hz

Attention is paid to the increasingly popular technology software-defined networks.<...>Of course, in this case, it is necessary to provide requirements for other indicators that define the concept QoS(quality of services).<...>Here is a description of such technologies as ATM, SDH, MPLS-TP, PBB-TE.<...>Attached to the manual is summary building principles software-defined networks that are gaining in Lately more and more popular.<...>The description of technology of virtualization of network functions is given NFV(Network Function Virtualization), compared SDN And NFV. <...>Physical Wednesday transmission data General characteristics physical environments. <...>Physical Wednesday transmission data (medium) can be a cable, the earth's atmosphere or outer space.<...> Cables higher categories have more turns per unit length.<...> Cables categories 1 are used where the requirements for bit rate are minimal.<...> Cables categories 2 were first used by IBM when building their own cable system.<...> Cables categories 4 is a slightly improved version cables categories 3. <...> high speed broadcast data based wireless media is discussed in Chapter 7.<...>The choice of network topology is the most important task to be solved during its construction, and is determined by the requirements for efficiency and structural reliability. <...>Work on the standardization of open systems began in 1977. In 1983, a reference model WOS- most general description structures for building standards.<...> Model WOS, which defines the principles of the relationship between individual standards, is the basis for the parallel development of many standards and provides a gradual transition from existing implementations to new standards.<...>reference model WOS does not define the protocols and interfaces of interaction, the structure and characteristics of the physical means of connection.<...>Third, network level, performs routing<...>

Network_technologies_of_high-speed_data_transmission._Tutorial_for_universities._-_2016_(1).pdf

UDC 621.396.2 LBC 32.884 B90 Reviewers: Doctor of Engineering. sciences, professor of tech. sciences, professor; Dr. Budyldina N. V., Shuvalov V. P. B90 Network technologies for high-speed data transmission. Textbook for universities / Ed. Professor V.P. Shuvalov. - M.: Hotline - Telecom, 2016. - 342 p.: ill. ISBN 978-5-9912-0536-8. In a compact form, the issues of building infocommunication networks that provide high-speed data transmission are outlined. Sections are presented that are necessary to understand how it is possible to provide transmission not only at high speed, but also with other indicators characterizing the quality of the service provided. The description of the protocols of different levels of the reference model of interaction of open systems, technologies of transport networks is given. The issues of data transmission in wireless communication networks and modern approaches that ensure the transmission of large amounts of information in acceptable periods of time are considered. Attention is paid to the increasingly popular technology of software-defined networks. For students studying in the direction of training "Infocommunication technologies and communication systems" qualifications (degrees) "bachelor" and "master". The book can be used to improve the skills of telecommunications workers. LBC 32.884 Budyldina Nadezhda Veniaminovna, Shuvalov Vyacheslav Petrovich Network technologies of high-speed data transfer Textbook for universities All rights reserved. Any part of this publication may not be reproduced in any form or by any means without the written permission of the copyright holder. Budyldina, V.P. Shuvalov L. D. G. Nevolin G. Dorosinsky

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Title Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 References for introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Chapter 1. Basic concepts and definitions. . . . . . . . . . . . . . . . . . . 6 1.1. Information, message, signal. . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.2. Information transfer rate. . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.3. The physical medium of data transmission. . . . . . . . . . . . . . . . . . . . . . . 14 1.4. Signal conversion methods. . . . . . . . . . . . . . . . . . . . . . . . . 22 1.5. Methods of multiple access to the environment. . . . . . . . . . . . . . . . . 31 1.6. Telecommunication networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 1.7. Organization of work on standardization in the field of data transmission. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 1.8. Reference model of open systems interaction. . . . . . . 47 1.9. Control questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 1.10. Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Chapter 2. Ensuring service quality indicators. . 58 2.1. Quality of service. General provisions. . . . . . . . . . . . . . . 58 2.2. Ensuring the fidelity of data transmission. . . . . . . . . . . . . . . . . . 64 2.3. Ensuring indicators of structural reliability. . . . . . . . 78 2.4. QoS routing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 2.5. Control questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 2.6. Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Chapter 3. Local networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 3.1. LAN protocols. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 3.1.1. Ethernet technology (IEEE 802.3). . . . . . . . . . . . . . . . . . 92 3.1.2. Token Ring Technology (IEEE 802.5). . . . . . . . . . . . . . . 93 3.1.3. FDDI technology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 3.1.4. Fast Ethernet (IEEE 802.3u) . . . . . . . . . . . . . . . . . . . . . . . . 96 3.1.5. 100VG-AnyLAN technology. . . . . . . . . . . . . . . . . . . . . . . 101 3.1.6. High speed Gigabit Ethernet technology. . . . . 102 3.2. Technical means that ensure the functioning of high-speed data transmission networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 3.2.1. Concentrators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 3.2.2. Bridges. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 3.2.3. Switches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 3.2.4. STP protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 3.2.5. Routers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 3.2.6. Gateways. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 3.2.7. Virtual local area networks (Virtual local area Network, VLAN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

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342 Contents 3.3. Control questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 3.4. Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 Chapter 4. Link layer protocols. . . . . . . . . . . . . . . . . . . . . . . 138 4.1. The main tasks of the link layer, protocol functions 138 4.2. Byte-oriented protocols. . . . . . . . . . . . . . . . . . . . . . . . 142 4.3. bit-oriented protocols. . . . . . . . . . . . . . . . . . . . . . . . . . 145 4.3.1. HDLC (High-Level Data Link Control) link layer protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 4.3.2. SLIP (Serial Line Internet Protocol) frame protocol. 152 4.3.3. PPP protocol (Point-to-Point Protocol - point-to-point protocol). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 4.4. Control questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 4.5. Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Chapter 5. Network and transport layer protocols. . . . . . . . 161 5.1. IP protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 5.2. IPv6 protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 5.3. RIP routing protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 5.4. OSPF Internal Routing Protocol. . . . . . . . . . . . . . 187 5.5. BGP-4 protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196 5.6. Resource Reservation Protocol - RSVP. . . . . . . . . . . . . . 203 5.7. RTP (Real-Time Transport Protocol) transfer protocol. . . . 206 5.8. DHCP (Dynamic Host Configuration Protocol). . . 211 5.9. LDAP protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 5.10. Protocols ARP, RARP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 5.11. TCP (Transmission Control Protocol). . . . . . . . . . . . 220 5.12. UDP (User Datagram Protocol) protocol. . . . . . . . . . . . . . . . . 229 5.13. Control questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 5.14. Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 Chapter 6. Transport IP networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 6.1. ATM technology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 6.2. Synchronous Digital Hierarchy (SDH). . . . . . . . . . . . . . . . . . . 241 6.3. Multiprotocol label switching. . . . . . . . . . . . . . . 245 6.4. Optical transport hierarchy. . . . . . . . . . . . . . . . . . . . . . . 251 6.5. Model and hierarchy of Ethernet for transport networks. . . . . . 256 6.6. Control questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 6.7. Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 Chapter 7. Wireless technologies of high-speed data transmission. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 7.1. Wi-Fi technology (Wireless Fidelity). . . . . . . . . . . . . . . . . . . . . . 262 7.2. WiMAX technology (Worldwide Interoperability for Microwave Access). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264

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343 7.3. Transition from WiMAX to LTE technology (LongTermEvolution). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 7.4. Status and prospects of high-speed wireless networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 7.5. Control questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 7.6. Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 Chapter 8. In Conclusion: Some Considerations on "What Should Be Done to Ensure High Speed ​​Data Transfer on IP Networks" . 279 8.1. Traditional data transmission with guaranteed delivery. Problems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280 8.2. Alternative data transfer protocols with guaranteed delivery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 8.3. Overload control algorithm. . . . . . . . . . . . . . . . . . . . . . . . . . . 285 8.4. Conditions for ensuring data transmission at high speed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287 8.5. Implicit problems of providing high-speed data transfer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297 8.6. Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 Appendix 1. Software-Defined Networks. . . . . . . . . . 302 P.1. General provisions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 P.2. OpenFlow protocol and OpenFlow switch. . . . . . . . . . . . . . 306 P.3. NFV Network Virtualization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 P.4. PCS standardization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 P.5. SDN in Russia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 P.6. Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320 Terms and definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322

Analyzing the historical experience of creating and developing network technologies for high-speed information transfer, it should be noted that the main factor that led to the emergence of these technologies is the creation and development of computer technology. In turn, the incentive to create computer technology (electronic computers) was the second World War. Deciphering the coded messages of the German agents required a huge amount of calculations, and they had to be done immediately after the radio interception. Therefore, the British government set up a secret laboratory to create an electronic computer called COLOSSUS. The famous British mathematician Alan Turing took part in the creation of this machine, and it was the world's first electronic digital computer.

The Second World War influenced the development of computer technology in the United States. The army needed firing tables to be used when aiming heavy artillery. In 1943, John Mowshley and his student J. Presper Eckert began to design an electronic computer, which they called ENIAC (Electronic Numerical Integrator and Computer - electronic digital integrator and calculator). It consisted of 18,000 vacuum tubes and 1,500 relays. ENIAC weighed 30 tons and consumed 140 kilowatts of electricity. The machine had 20 registers, each of which could hold a 10-bit decimal number.

After the war, Moshli and Eckert were allowed to organize a school where they talked about their work to fellow scientists. Soon, other researchers took up the design of electronic computers. The first working computer was the EDS AC (1949). This machine was designed by Maurice Wilkes at the University of Cambridge. Then came JOHNIAC - at the Rand Corporation, ILLIAC - at the University of Illinois, MANIAC - at the Los Alamos laboratory and WEIZAC - at the Weizmann Institute in Israel.

Eckert and Moushley soon began work on the EDVAC (Electronic Discrete Variable Computer) machine, followed by the development of UNIVAC (the first electronic serial computer). In 1945, John von Neumann, who created the principles of modern computer technology, was involved in their work. Von Neumann realized that building computers with lots of switches and cables was time consuming and very tedious. He came to the idea that the program should be represented in the computer's memory in digital form along with the data. He also noted that the decimal arithmetic used in the ENIAC machine, where each digit was represented by 10 vacuum tubes (1 tube on, 9 off), should be replaced by binary arithmetic. The von Neumann machine consisted of five main parts: memory - RAM, processor - CPU, secondary memory - magnetic drums, tapes, magnetic disks, input devices - reading from punched cards, information output devices - printer. It was the need to transfer data between parts of such a computer that stimulated the development of high-speed data transmission and the organization of computer networks.

Initially, punched tapes and punched cards were used to transfer data between computers, then magnetic tapes and removable magnetic disks. In the future, special software (software) appeared - operating systems that allow many users from different terminals to use one processor, one printer. At the same time, the terminals of a large machine (mainframe) could be removed from it at a very limited distance (up to 300-800m). With the development of operating systems, it became possible to connect terminals to mainframes using public telephone networks with an increase in both the number of terminals and the corresponding distances. However, there were no general standards. Each manufacturer of large computers developed its own rules (protocols) for connection and, thus, the choice of manufacturer and data transfer technology for the user became lifelong.

The advent of low-cost integrated circuits has made computers smaller, more affordable, more powerful, and more specialized. Companies could already afford to have several computers designed for different departments and tasks and released by different manufacturers. In this regard, a new task has appeared: connecting groups of computers to each other (Interconnection). The very first companies that these "islands" connected were IBM and DEC. DEC's data transfer protocol was DECNET, which is no longer used today, and IBM's was SNA (System Network Architecture - the first network data transfer architecture for IBM 360 series computers). However, computers from one manufacturer were still limited to connecting with their own kind. When connecting computers from another manufacturer, software emulation was used to simulate the operation of the desired system.

In the 60s of the last century, the US government set the task of ensuring the transfer of information between computers of various organizations and funded the development of standards and protocols for the exchange of information. ARPA, the research agency of the US Department of Defense, took up the task. As a result, it was possible to develop and implement the ARPANET computer network, through which US federal organizations were connected. The TCP/IP protocols and the US Department of Defense (DoD) Internet-to-Internet communication technology were implemented in this network.

Personal computers that appeared in the 80s began to be combined into local networks (LAN - Local Area Network).

Gradually, more and more manufacturers of equipment and, accordingly, software (MO) appear, active developments are being carried out in the field of interaction between equipment from different manufacturers. Currently, networks that include equipment and MO from different manufacturers are called heterogeneous networks(diverse). The need to “understand” each other leads to the need to create not corporate data transfer rules (for example, SNA), but common ones for everyone. There are organizations that create standards for data transmission, the rules are determined by which private clients, telecommunications companies can work, the rules for combining heterogeneous networks. Such international standardizing organizations include, for example:

  • ITU-T (ITU-T is the Telecommunication Standardization Sector of the International Telecommunication Union, the successor to the CCITT);
  • IEEE (Institute of Electrical and Electronics Engineers);
  • ISO (International Organization for Standardization);
  • EIA (Electronic Industries Alliance);
  • TIA (Telecommunications Industry Association).

At the same time, private companies do not stop developing (for example, Xerox developed Ethernet technology, and CISCO developed 1000Base-LH and MPLS technology).

With the reduction in the cost of technology, organizations and companies have been able to combine their computer islands located at different distances (in different cities and even continents) into their own private - corporate network. The corporate network can be built on the basis of international standards (ITU-T) or standards of one manufacturer (IBM SNA).

With the further development of high-speed data transmission, it became possible to combine various organizations into one network and connect to it not only members of a single company, but any person who follows certain access rules. Such networks are called global. Note that a corporate network is a network that is not open to any user, global network, on the contrary, is open to any user.

conclusions

At the moment, almost all networks are heterogeneous. Information is born on the basis of corporate networks. The main volumes of information circulate in the same place. Hence the need to study them and the ability to implement such networks. However, access to information is increasingly open to various users, free from a particular corporation, and hence the need to be able to implement global networks.

Additional Information

Control questions

  • The network of IBM, whose offices are in Chicago, Barcelona, ​​Moscow, Vienna, is:
    • global
    • corporate
    • heterogeneous
    • all previous definitions are valid
  • The purpose of creating an organization's computer network is (indicate all correct answers):
    • sharing network resources with users, regardless of their physical location;
    • sharing information;
    • interactive entertainment;
    • the possibility of electronic business communication with other companies;
    • participation in the system of dialogue messages (chats).

Textbook for universities / Ed. professor V.P. Shuvalova

2017 G.

Circulation 500 copies.

Format 60x90/16 (145x215 mm)

Version: paperback

ISBN 978-5-9912-0536-8

BBC 32.884

UDC 621.396.2

Vulture UMO
Recommended by the UMO for education in the field of infocommunication technologies and communication systems as a textbook for students of higher educational institutions studying in the direction of training 11.03.02 and 11.04.02 - "Infocommunication technologies and communication systems" qualifications (degrees) "bachelor" and "master" »

annotation

In a compact form, the issues of building infocommunication networks that provide high-speed data transmission are outlined. Sections are presented that are necessary to understand how it is possible to provide transmission not only at high speed, but also with other indicators characterizing the quality of the service provided. The description of the protocols of different levels of the reference model of interaction of open systems, technologies of transport networks is given. The issues of data transmission in wireless communication networks and modern approaches that ensure the transmission of large amounts of information in acceptable periods of time are considered. Attention is paid to the increasingly popular technology of software-defined networks.

For students studying in the direction of training bachelors "Infocommunication technologies and communication systems (degrees) "bachelor" and "master". The book can be used to improve the skills of telecommunications workers.

Introduction

References for introduction

Chapter 1. Basic concepts and definitions
1.1. Information, message, signal
1.2. Information transfer rate
1.3. Physical media
1.4. Signal conversion methods
1.5. Media Access Methods
1.6. Telecommunication networks
1.7. Organization of work on standardization in the field of data transmission
1.8. Reference Model for Open Systems Interconnection
1.9. Control questions
1.10. Bibliography

Chapter 2: Ensuring Service Quality Metrics
2.1. Quality of service. General provisions
2.2. Ensuring the fidelity of data transmission
2.3. Ensuring indicators of structural reliability
2.4. QoS routing
2.5. Control questions
2.6. Bibliography

Chapter 3 Local Area Networks
3.1. LAN protocols
3.1.1. Ethernet technology (IEEE 802.3)
3.1.2. Token Ring Technology (IEEE 802.5)
3.1.3. FDDI Technology
3.1.4. Fast Ethernet (IEEE 802.3u)
3.1.5. 100VG-AnyLAN technology
3.1.6. High speed Gigabit Ethernet technology
3.2. Technical means ensuring the functioning of high-speed data transmission networks
3.2.1. Hubs
3.2.2. Bridges
3.2.3. Switches
3.2.4. STP protocol
3.2.5. Routers
3.2.6. Gateways
3.2.7. Virtual Local Area Networks (VLANs)
3.3. Control questions
3.4. Bibliography

Chapter 4 Link Layer Protocols
4.1. Main tasks of the link layer, protocol functions 137
4.2. Byte oriented protocols
4.3. Bit-oriented protocols
4.3.1. HDLC (High-Level Data Link Control) link layer protocol
4.3.2. Frame protocol SLIP (Serial Line Internet Protocol). 151
4.3.3. PPP (Point-to-Point Protocol)
4.4. Control questions
4.5. Bibliography

Chapter 5 Network and Transport Layer Protocols
5.1. IP protocol
5.2. IPv6 protocol
5.3. RIP routing protocol
5.4. OSPF Internal Routing Protocol
5.5. BGP-4 protocol
5.6. Resource Reservation Protocol - RSVP
5.7. RTP (Real-Time Transport Protocol) transfer protocol
5.8. DHCP (Dynamic Host Configuration Protocol)
5.9. LDAP protocol
5.10. Protocols ARP, RARP
5.11. TCP (Transmission Control Protocol)
5.12. UDP (User Datagram Protocol)
5.13. Control questions
5.14. Bibliography

Chapter 6 Transport IP Networks
6.1. ATM Technology
6.2. Synchronous Digital Hierarchy (SDH)
6.3. Multiprotocol Label Switching
6.4. Optical transport hierarchy
6.5. Ethernet Model and Hierarchy for Transport Networks
6.6. Control questions
6.7. Bibliography

Chapter 7 High Speed ​​Wireless Technology
7.1. Wi-Fi Technology (Wireless Fidelity)
7.2. WiMAX technology (Worldwide Interoperability for Microwave Access)
7.3. Transition from WiMAX to LTE technology (LongTermEvolution)
7.4. State and prospects of high-speed wireless networks
7.5. Control questions
7.6. Bibliography

Chapter 8. In Conclusion: Some Thoughts on "What Should Be Done to Ensure High Speed ​​Data Transfer on IP Networks"
8.1. Traditional data transmission with guaranteed delivery. Problems
8.2. Alternative data transfer protocols with guaranteed delivery
8.3. Congestion control algorithm
8.4. Conditions for ensuring high speed data transmission
8.5. Implicit problems of providing high-speed data transfer
8.6. Bibliography

Appendix 1: Software Defined Networks
P.1. General provisions.
P.2. OpenFlow Protocol and OpenFlow Switch
P.3. NFV Network Virtualization
P.4. Standardization of PCS
P.5. SDN in Russia
P.6. Bibliography

Terms and Definitions