Computer_Engineering_print_new2

Preview:

Relative clauses with a participle are often used in technical descriptions. They allow you to provide a lot of information about a noun using as few words as possible.

Study these examples.

1.The technology needed to set up a home network.

2.PCs equipped with Ethernet adapters.

3.Network modem allowing clients to access the Internet simultaneously.

4.Data line linking client to server.

We can use the passive participle as in sentences 1 and 2.

1.The technology needed to set up a home network. = technology which is needed.

2.PCs equipped with Ethernet adapters = PCs which are equipped.

We can use an active participle as in sentences 3 and 4.

3.Network modem allowing clients to access the Internet simultaneously = modem which allows clients to access the Internet simultaneously.

4.Data line linking client to server = data line which links client to server.

52 Computer Engineering

SPECIALIST READING A: Computer Networking

10. Scan the text and say which paragraph tells us about:

a.types of networks;

b.history of network development;

c.what computer networking is.

11. Now study the text and decide where the following sentences go in the text.

a.…the data is transferred over sets of radio transceivers;

b.A peer-to-peer network is where each client shares their resources with other workstations in the network;

c.…the switching capabilities they perform;

d.…a sub-discipline of telecommunications, computer science, information technology and/or computer engineering;

e.…human users by carrying instructions between them;

f.…the set of subnets, and aggregates of subnets;

g.some form of communications security mechanism;

h.…to connect and communicate through and between them.

Computer networking is the engineering discipline

concerned with communication between computer

systems or devices. Networking, routers, routing protocols, and networking over the public Internet have their specifications defined in documents called RFCs.

Computer networking is sometimes considered 1)_____________________. Computer networks rely heavily upon the theoretical and practical application of these scientific and engineering disciplines.

A computer network is any set of computers or

devices connected to each other with the ability to

exchange data. Local area network (LAN) is a network that spans a relatively small space and provides services to a small number of people. The first LAN was invented by a Law Doctor in 1978. Depending on the number of people that use a Local Area Network, a peer-to-peer or client-server method of networking may be used. 2)_____________________. Examples of peer-to- peer networks are small office networks where resource use is minimal and a home network. A client-server network is where every client is connected to the server and each other. Client-server networks use servers in different capacities. These can be classified into two types: single-service servers, where the server performs one task such as file server, print server, etc.; while other servers can not only perform in the capacity of file servers and print servers, but they also conduct calculations and use these to provide information to clients (Web/Intranet Server). Computers linked via Ethernet Cable, can be joined either directly or via a network hub that allows multiple connections.

Wide area network (WAN) is a network where a wide variety of resources are deployed across a large domestic area or internationally. An example of this is a multinational business that uses a WAN to interconnect their offices in different countries. The largest and best example of a WAN is the Internet, which is a network comprised of many smaller networks. The Internet is considered the largest network in the world. The PSTN (Public Switched Telephone Network) also is an extremely large network that is converging to use Internet technologies, although not necessarily through the public Internet. A Wide Area Network involves communication through the use of a wide range of different technologies. These technologies include Point-to-Point WANs such as Point-to-Point Protocol (PPP) and High-Level Data Link Control (HDLC), Frame

Relay, ATM (Asynchronous Transfer Mode) and Sonet (Synchronous Optical Network). The difference between the WAN technologies is based on 3)______________________ and the speed at which sending and receiving bits of information (data) occur. Wireless LANs and WANs (WLAN & WWAN) are basically the same as a LAN or a WAN but there are no wires between hosts and servers. 4)_____________________. These types of networks are beneficial when it is too costly or inconvenient to run the necessary cables.

Metropolitan Area Network (MAN) is a network that is too large for even the largest of LAN's but is not on the scale of a WAN. It also integrates two or more LAN networks over a specific geographical area (usually a city) so as to increase the network and the flow of communications. The LAN's in question would usually be connected via "backbone" lines.

All networks are interconnected to allow communication with a variety of different kinds of media, including twisted-pair copper wire cable, coaxial cable, optical fiber, and various wireless technologies. The devices can be separated by a few meters (e.g. via Bluetooth) or nearly unlimited distances (e.g. via the interconnections of the Internet).

Informally, the Internet is the set of users, enterprises, and content providers that are interconnected by Internet Service Providers (ISP). From an engineering standpoint, the Internet is 5)_____________________, which share the registered IP address space and exchange information about the reachability of those IP addresses using the Border Gateway Protocol. Typically, the human-readable names of servers are translated to IP addresses, transparently to users, via the directory function of the Domain Name System (DNS).

Over the Internet, there can be business-to-business (B2B), business-to-consumer (B2C) and consumer-to- consumer (C2C) communications. Especially when money or sensitive information is exchanged, the communications are apt to be secured by 6)_____________________.

Intranets and extranets can be securely superimposed onto the Internet, without any access by general Internet users, using secure Virtual Private Network (VPN) technology.

Before the advent of computer networks that were based upon some type of telecommunications system, communication between calculation machines and early computers was performed by 7)_____________________.

Computer Engineering 53

Many of the social behavior seen in today's Internet was demonstrably present in nineteenth-century telegraph networks, and arguably in even earlier networks using visual signals.

In September 1940 George Stibitz used a teletype machine to send instructions for a problem set from his Model K at Dartmouth College in New Hampshire to his Complex Number Calculator in New York and received results back by the same means. Linking output systems like teletypes to computers was an interest at the Advanced Research Projects Agency (ARPA) when, in 1962, J.C.R. Licklider was hired and developed a working group he called the "Intergalactic Network", a precursor to the ARPANet.

In 1964, researchers at Dartmouth developed the Dartmouth Time Sharing System for distributed users of large computer systems. The same year, at MIT, a research group supported by General Electric and Bell Labs used a computer (DEC's PDP-8) to route and manage telephone connections.

Throughout the 1960s Leonard Kleinrock, Paul Baran and Donald Davies independently conceptualized and developed network systems which used datagrams or packets that could be used in a packet switched network between computer systems.

1965 Thomas Merrill and Lawrence G. Roberts created the first wide area network (WAN).

The first widely used PSTN switch that used true computer control was the Western Electric 1ESS switch, introduced in 1965.

In 1969 the University of California at Los Angeles, SRI (in Stanford), University of California at Santa Barbara, and the University of Utah were connected as the beginning of the ARPANet network using 50 kbit/s circuits. Commercial services using X.25, an alternative architecture to the TCP/IP suite, were deployed in 1972.

Computer networks and the technologies needed 7)_____________________, continue to drive computer hardware, software, and peripherals industries. This expansion is mirrored by growth in the numbers and types of users of networks from the researcher to the home user.

Today, computer networks are the core of modern communication. All aspects of the PSTN are computercontrolled, and telephony increasingly runs over the Internet Protocol. The scope of communication has increased significantly in the past decade and this boom in communications would not have been possible without the progressively advancing computer network.

SPECIALIST READING B: TCP/IP vs. PPP

15.Skim through the text and find explanations to the abbreviations given in the titles. Then read the text thoroughly and do the tasks below.

16.Read the text and mark the equivalents for the following Russian words and phrases:

несовместимый;

проверка целостности данных;

перемешивать;

приводить в действие;

подпрограмма;

подключаться;

узел;

назначение;

поиск данных;

последовательное подсоединение;

нуль-модемный кабель;

система соединения типа точка-точка;

полоса пропускания;

входящее соединение;

одновременно;

последовательный порт;

авторизация.

Computer Engineering 55

TCP/IP

By the mid-1970s, many government agencies were on the ARPA net, but each was running or

network developed for their specific project. All were capable networks, but all spoke different languages. What was clearly needed to make things work smoothly was a set of networking protocols that would tie together disparate networks and enable them to communicate with each other. The solution was found in 1982.

TCP stands for Transmission Control Protocol; IP is the abbreviation for Internet Protocol. With the advent of TCP/IP, the word Internet - which is a portmanteau word for interconnected networks - entered the language.

The TCP portion of the TCP/IP provides data transmission verification between client and server.

If data is lost or scrambled, TCP triggers retransmission until the errors are corrected.

Package of subroutines that provide access to TCP/IP protocols is called a socket.

The IP portion of TCP/IP moves data packets

from node to node. It decodes addresses and rout

data to designated destinations. The Internet Protocol (IP) is what creates the network networks, or Internet, by linking systems at different levels. It can be used by small computers communicate across a LAN (Local Area Network) in the same room or with computers networks around the world. Individual computers connected via a LAN (either Ethernet or token ring) share the LAN setup with both TCP/IP and other network protocols, such as Novell or Windows for Workgroups. One computer on the LAN then provides the TCP/IP connection to the outside world.

TCP/IP has been ported to most computer system including personal computers, and has become the new standard in internetworking. It is 1 protocol set that provides the infrastructure for the Internet today. TCP/IP comprises over 100 different protocols. It includes services for remote logon, file transfers, and data indexing and retrieval, among others.

English for Special Purposes

56 Computer Engineering

PPP

One of the most widely used protocols is the Point to Point Protocol. PPP is a mechanism for creating and running IP and other network protocols over a serial link – be that a direct serial connection (using a null-modem cable), over a telnet established link, or a link made using modems and telephone lines (and of course ISDN).

Using PPP, you can connect your PC to a PPP server and access the resources of the network to which the server is connected as if you were directly connected to that network. You can also set up your PC as a PPP server, so that other computers can dial into your computer and access the resources on your local PC and/or network. You can also use PPP on two PCs to link together two networks (or a local network to the Internet), creating a Wide Area Network (WAN).

One major difference between serial based PPP and an Ethernet connection is of course speed

– a standard Ethernet connection operates at 10 Mbs or 100 Mbs maximum theoretical throughput, whereas an analogue modem operates at speeds up to 56 kbps. Also, depending on the type of PPP connection, there may be some limitations in usage of some applications and services.

PPP is strictly a peer to peer protocol; there is (technically) no difference between the machine that dials in and the machine that is dialed into. However, for clarity's sake, it is useful to think in terms of servers and clients. When you dial into a site to establish a PPP connection, you are a client. The machine to which you connect is the server. When you are setting up a box to receive and handle dial-in PPP connections, you are setting up a PPP server. Any PC can be both a PPP server and client - even simultaneously if you have more than one serial port (and modem if necessary).

The machine that initiates the call as the CLIENT, whilst the machine that answers the telephone, checks the authentication of the dial in request is referred to as the SERVER. The use of PPP as a client to link one or more machines at a location into the Internet is, probably, the one in which most people are interested.

17. Reread the text and answer the following questions

1.What determined the necessity of creating a set of networking protocols?

2.What is the role of the TCP portion of the TCP/IP protocol?

3.What is a socket?

4.What does the IP portion do?

5.What is a function of a LAN?

6.How many protocols does TCP/IP comprise?

7.What is the PPP used for?

8.In what way does it differ from the Ethernet connection?

9.How can you apply client server relations in the PPP?

10.Explain the term “peer-to-peer system”.