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1. Introduction

2. Red Concept

3. Topologies

4. LANs

5. WAN

6. Components.

7. OSI Model

8. Under Windows Networks

9. Conclusions

1. Introduction

The study of computer networks comprises a fairly broad, as emphasized in everything related to the computer network is complex due to the constant development in this field is given each time with more and better features related to administrative tools system. Is this part of the administration that requires study and availability of time, so the project will focus on the most important theoretical aspects of current technology in network design and implementation.

The Internet is a great progress in the conquest of networking software, powerful and strong, can adapt to different computers and users.

In networks there is no defined standard or something, any decision we can find limits, since there is no established OS, all are in the process.

Networks tend to grow and innovate, first connect a few people and then everybody wants to connect, to find it necessary to connect to an email.

The manual posted on the website, is an application developed in graphical environment, which facilitates the user in understanding providing a source of reference and applicability to real world problems.

Elsewhere on the network installation manual, it has many aids consultation, facilitating a visible classroom practice.

With the network installation manual posted on the website, we present how to install networks BUS topology, star topology, star topology Wired, tree topology and their classification as LAN, MAN and WAN.

With the development of the project has created a query tool accessible and straightforward for those with minimal knowledge of network installation and also for those who want to deepen knowledge already acquired.

With all these requirements we present this project, hoping that in the, is a source of consultation that is appropriate to the needs of users.

2. Red Concept

A network consists of two or more computers together to share resources such as files, printers, CD-Roms or which are capable of electronic communications. Networks are linked by cable, telephone lines, radio waves, satellite, etc..


Its main objective is to make all data and computer programs are available to anyone on the network that requests it, regardless of the physical location of the resource and the user.

Another objective is to provide high reliability by having alternative sources of supply, meaning that all files could double in two or three machines, so that if one is not available, one could use the other copies. Similarly, the presence of multiple CPU means that if one of them fails, the others may be able to undertake their work, although its overall performance is lower.

The economic savings because small computers has better cost / performance ratio, compared with that offered by large machines.

It provides a powerful means of communication between people who are in places far between.

Basic classification of networks.

LAN / LAN (Local Area Network)

It is a network that covers a small extent as a company, a university, a college, etc.. There will usually distension between two computers if more than one kilometer.

A typical configuration in a local area network is to have a computer called file server that stores all the software control of the network and the software that is shared with other computers on the network. The computers that are file servers are called workstations. These are usually less powerful and have custom software for each user. Most LANs are connected by cables and network cards, one in each team.

Metropolitan area network / MAN (Metropolitan Area Network)

Metropolitan area networks covering larger areas such as a city or a district. By interconnecting LANs computing are distributed to different parts of the district. Libraries, universities or government agencies are interconnected through such networks.

Wide Area Network / WAN (Wide Area Network)

Wide area networks cover large geographical regions as a country, a continent or even the world.

Transoceanic cable or satellites are used to link points with a large distance between them.

With the use of a WAN can connect from Spain to Japan without having to pay huge amounts of phone. The implementation of a wide area network is very complicated. Multiplexers are used to connect networks to metropolitan global networks using techniques that allow networks of different characteristics can communicate without problem. The best example of a wide area network is the Internet.

Network cabling.

The cable is the medium through which the information flowing through the network. There are different types of cable commonly used in LANs. A network can use one or more types of cable, although the cable type will always be subject to the topology of the network, the type of network you use and the size of this.

These are the cable types used in LANs:

Cable unshielded twisted pair / UTP Unshielded twisted pair.

Shielded twisted pair cable / STP twisted Shieles

Coaxial Cable

Fiber Optic Cable

LAN without cabling.

Cable unshielded twisted pair / Unshielded Twisted Pair (UTP)

This type of cable is the most used. Has a variant shielded unshielded variant but usually the best option for an SME.

The quality of the cable and consequently the amount of data that is capable of transmitting vary depending on the category of the cable. The rankings range from telephone cable, which transmits only the human voice to the Category 5 cable capable of transferring 100 Megabytes per second.

UTP Category



Category 1

Vos (telephone wire)

Category 2

Data to 4 Mbps (LocalTalk)

Category 3

Data to 10 Mbps (Ethernet)

Category 4

Data to 20 Mbps / 16 Mbps Token Ring)

Category 5

Data at 100 Mbps (Fast Ethernet)

The difference between categories is the tension. A greater tension greater data transmission capability. The use of cables category 3-5 for the implementation of networks in SMEs or small and medium enterprises.

It is however advisable to use Category 5 cables as these technologies allow migration of 10Mb to 100Mb technology

UTP connector

The standard for UTP cable connectors is the RJ-45. This is a plastic connector similar to the connector of the telephone cable. The acronym refers to Standard RJ Registerd Jack, created by the telephone industry. This standard is responsible for defining the placement of the wires in pin.

Pantallar Twisted Pair / Shielded Twisted Pair (STP)

A disadvantage of UTP is that it is susceptible to electrical interference. For environments with such problems there is a type of UTP cable leading shielded, this means protection against electrical interference. This type of cable is generally used in Token Ring topology networks.

Coaxial Cable

The coaxial cable includes a copper conductor inside. This is enveloped by an insulator to separate a shaped metal shield that isolates the power grid from external interference.

Although installing coaxial cable is more complicated than that of UTP, this has a high degree of resistance to interference, can also be connected with greater distances than twisted-pair cables.

Coaxial Cable Types:

Fine or thin coaxial cable coaxial

Thick thick coaxial cable or coaxial.

You may hear references to the coaxial cable or 10Base2 thin as thinnet. They refer to a network with an Ethernet-type thin coaxial cable. Where 2 means that the largest segment is 200 meters, in practice reduced to 185 m. The coaxial cable is popular in BUS topologies.

Also referenced as the thick coaxial cable or 10Base5 thicknet. This refers to an Ethernet type network with a thick coaxial cabling, where 5 means that the largest possible segment is 500 meters. Coaxial cable is very popular in the bus topology networks. The thick coaxial cable has an additional plastic layer that protects from moisture copper conductor. This makes this cable a great choice for extensive bus networks, although it should be noted that this wire is hard to bend.

Coaxial Cable Connector:

The most widely used is the BNC connector, whose initials are bayonet Neill-Concelman. BNC connectors can be of three types:

Fiber Optic Cable

The optical fiber consists of a glass center surrounded by several layers of protective material. What is transmitted electrical signals but not light thus eliminating the problem of interference. This makes it ideal for environments where there is large amount of electrical interference. It is also used in connecting networks between buildings due to its immunity to moisture and sunlight.

With an optical fiber signals can be transmitted over much greater distances than coaxial cable or twisted pair. Also the amount of information that can be transmitted is greater so it is ideal for networks through which they want to perform video conferencing and interactive services. Cost is similar to coaxial cable or UTP cable but difficulties of installation and modification are greater. Sometimes 10BaseF hear reference to this type of wiring; these acronyms speak of an Ethernet network with fiber optic cabling.

The main features are

The outer insulation is Teflon or PVC miss.

Kevlar fibers help give strength to the cable and makes it harder to break.

Using a plastic coating to accommodate the central fiber.

The center of the cable is cast glass or plastic fibers.

Summary wires


Cable Type

Maximum length

10 base t


100 meters

10 BASE 2

Thin Coaxial

185 meters

10 BASE 5

Thick Coaxial

500 meters

10 Base F

Optical fiber

2000 meters

LAN without cabling

Not all networks are deployed on a wire, some use radio signals or infrared beams high frequency to communicate. Each lattice point has an antenna from which transmits and receives. For longer distances you can use mobile phones or satellites.

This type of connection is especially suited for use with laptops or old buildings where it is impossible to install wiring.

The disadvantages of this type of network are its high cost, its susceptibility to electromagnetic interference and low security they offer. They are also slower than wired networks using.

3. Topologies

The main types of physical topologies are:

Topology BUS / Linear Bus

Topology Star / Star

Star topology Wired / Star – Wired Ring.

Topology Tree / Tree

Topology BUS / Linear Bus

It consists of a cable with a terminator at each end of which hang all elements of a network loess. All network nodes are attached to this cable. This wire is called “Backbone Cable”. Ethernet and LocalTalk can use this topology.

Advantages of bus topology.

It is easier to connect new nodes to the network

Requires less cable than a star topology.

Disadvantages of bus topology.

The entire network would fall had a break in the main cable.

Terminators is required.

It is difficult to detect the source of a problem when the entire network down.

Should not be used as the only solution in a large building.

Topology Star / Star

Is a star topology every node in the network, they are connected to a hub or hub.

The data is flowing from the emitter these networks to the hub, it performs all the functions of the network also acts as an amplifier of the data.

Advantages of Star Topology

Easy installation

Ability to turn off network elements without causing problems.

Easy for fault detection and repair.

Disadvantages of the star topology.

Requires more cable than bus topology.

A fault in the concentrator leads to isolation of all nodes connected to it.

They have to buy hubs or concentrators.

Star topology Wired / Star-Wired Ring.

Physically resembles a star topology but the type of hub used, the handles MAU internally interconnected in a ring network.

This type is used in Token Ring networks

Topology Tree / Tree

The tree topology combines characteristics of the star topology with the BUS. Consists of a set of subnetworks connected to a BUS star. This topology facilitates network growth.

Advantages of the tree topology.

Point to point wiring to individual segments.

Supported by many software vendors and hardware.

Disadvantages of the tree topology.

The measure of each segment is determined by the type of cable used.

If you come down the main segment entire segment goes down with him.

It is more difficult to setup.

Summary physical topology:






Twisted Pair

Optical fiber


Local Talk


Twisted Pair

Optical fiber


Local Talk

Star in Ring

Twisted Pair

Token Ring



Twisted Pair

Optical fiber


4. LANs

A protocol is a set of rules governing communication between computers on a re. These standards specify what type of cables are used, what types will be used, which will have the network topology, which will speed communications and that way you will access to the transmission channel.

The most popular standards are:



Token Ring


Ethernet is now the standard for local area networks. Ethernet is defined as a multiple access mode and collision detection is the known Carrier Sense Multiple Access / Collision Detection (CSMA / CD). When a station wants to access the network listens if any transmission in progress and if not transmitted. It is the case that two broadcast networks and detecting probability of emitting the same time a collision occurs this is resolved by the collision sensors which detect this and force a retransmission of the information.

Transmission speeds:

Ethernet type





10 base 5


500 m

Coaxial Coarse

10 Base 8



Coaxial Fine

10 Base T




10 Base F



Optical fiber

Local Talk

The LocalTalk protocol developed by Apple Computer, Inc. for Macintosh computers. The media access method is the SCMA / CA. (Carriewr Sense Multiple Access with Collision Avoidance) This method differs in that the computer announces its transmission before it can proceed. Using LocalTalk adapters and special UTP cable can create a computer network through the serial port. The operating system of these relationships provides point to point without additional software although you can create a client-server network with AppleShare software.

With the LocalTalk protocol can use bus topologies, star or tree using UTP but the transmission rate is lower than Ethernet.

Token Ring.

The Token Ring protocol was developed by IBM in the mid 80s. The medium access mode is based on the transfer of the witness or token passing. In a Token Ring network computers are connected in a ring. A witness or electronic token from one computer to another.

When you receive this witness is ready to send data. They travel around the ring to reach the receiving station. Token Ring networks are mounted on typologies wired star or star-wired with twisted pair or fiber optic. It can transmit information at 4 or 16 Mbps. This technology is currently being displaced by the rise of Ethernet.

Summary protocols:






Twisted Pair


Optical fiber

10 Mbps




Fast Ethernet

Twisted Pair

Optical fiber

23 Mbps



Local Talk

Twisted Pair

23 Mbps



Token Ring

Twisted Pair

4 Mbps –

16 Mbps


Wired Ring

5. WAN

Converting a wide area network (WAN). Almost all domestic network operators (as DBP in Germany or British Telecom. In England). They offer services to interconnect computer networks ranging from simple data links operating at low speed based on the public telephone network to complex high-speed services (such as Frame Relay and SMDS-Synchonous Multimegabit Data Service.) Suitable for LAN interconnection. These data services are often called high speed broadband connections. Is expected to provide the necessary links between LLAN to make possible what has been called the information superhighway.

In conclusion a WAN is a network in which data can be transmitted over long distances, connecting communication facilities between different locations within a country. In these networks usually are involved telephone companies.

Types of Networks

Networks as the use by the user can be: shared or exclusive.

Dedicated networks or exclusive.

Are those because of security, speed or absence of another network, connecting two or more points exclusively. This type of network can be structured in networks point to point or multipoint networks.

To-peer networks. – Allow direct online connection between terminals and computers.

The advantage of this type of connection is in the high transmission speed and security in the absence having connection with other users. Its disadvantage is the high price of this type of network.

Multipoint networks. – Allows the union of several computer terminals to their corresponding sharing a single transmission line. The advantage is the lowering of the cost, but loses speed and security.

Such networks require signal amplifiers and disseminators multiplexers or dedicated lines that allow sharing.

Shared Networks

Are those to which is attached a large number of users sharing all the transmission needs even with transmissions from other natures. The conventional networks are packet switching and circuit switching.

Packet switching networks. – Are networks in which nodes are processors concentration regulating packet traffic.

Package. – A small part of the information that each user wants to transmit. Each package consists of information, the destination identifier and some control characters.

Circuit-switched networks. – Are networks in which the switching centers establish a dedicated circuit between two communicating stations.

Integrated Services Digital Network (ISDN). – Technological developments are based on switching and digital transmission. The ISDN is a general-purpose fully digital capable of integrating a wide range of services such as voice, data, image and text.

The ISDN requires installation of digital exchanges.

Networks based on services that satisfy the users are classified as:

Networks for basic transmission services. – Are characterized by servicing without altering the information they convey. Such are the dedicated networks, the telephone network and circuit switched networks.

Networks for value added services. – Are those that in addition to the transmission of information, acting on it somehow.

Belong to this type of network: networks that manage messaging, electronic funds transfer, access to large databases, videotex, teletext, etc..

Networks as the service is performed about the company can be divided into:

Intrafirm networks. – Are those in which the equipment interconnection service is performed at the enterprise level.

Inter Networks. – Are those that provide equipment interconnection service between two or more companies.

Networks according to property belonging can be:

Private Networks. – Networks are managed by individuals, companies or organizations of private nature. They only have access to the terminals of the owners.

Public networks. – Those that belong to state agency, and are open to anyone who requests it by the corresponding contract.

Eg telegraph networks, telephone networks, special networks for data transmission.

6. Components.

Computer networks are assembled with a number of components in common use and which is more or less always appears in any installation.


The file servers are the heart of most networks. These computers with lots of RAM, a huge hard drive or more and a fast network card. The network operating system is running on these servers and shared applications.

A print server will monitor network traffic because this is the one that demands access to workstations and provide them with the services they ask printers, files, Internet, etc.. It is necessary to have a computer capable of storing information very quickly and just as quickly share.


Are the computers connected to the server. The workstations should not be as powerful as the server, you simply need a network card, cabling relevant and necessary software to communicate with the server. A workstation may lack drive and hard drive and work directly on the server. Almost any computer can act as a workstation.

Network Card

The network card or NIC is physically connecting the computer to the network. Network cards are of course popular Ethernet cards, LocalTalk connectors also exist and Token Ring cards.

Ethernet card with RJ-45

LocalTalk connectors are used for Mac computers, connecting to the parallel port. In comparison with Ethernet speed is very low, compared with 10 230KB or 100 MB of the first.

Token Ring cards are similar to Ethernet cards but the connector is different, usually a nine-pin DIM.

Concentrators or Hubs.

A hub or Hub is an element that provides a central connection for all network cables. Hubs are boxes with a number of connectors, more usually RJ.45 further another different type connector for linking to another network type.

The smart guy’s information sent only to those who have arrived while the normal send information to all points of the network being the workstations which are left to decide whether or not that information.

Special outputs are provided for connecting to one another hub connectors allowing network extensions.


When a signal travels along a cable is losing strength as it progresses. This loss of power can cause data loss. The repeaters amplify the signal received thus allowing the distance between two points in the network is greater than a single cable allows.

Bridges and Bridges.

The Bridges are used to segment large networks into smaller networks, for other different small network while all internal traffic will continue on the same network. This is achieved by reducing network traffic.

7. OSI Model

The OSI Network Model

Although at present we seem simple network two computers, is a complex engineering problem. When addressing problems of this magnitude, how to solve the problem is usually divided into small problems big. This is what the network model proposed OSI (Open Systems Interconnection), published by the ISO international organization, with the aim that the nodes that form a network, even from different manufacturers, are able to communicate without problem.

The communication protocol constitutes a software standard, which is responsible for controlling communication between two stations, the term “standard” means that this element must meet certain requirements, which are imposed by OSI.

This model divides the “big problem” in 7 small problems that are known as the seven-layer OSI network.

Consider the seven levels:

Physical Level

Data Link Layer

Network Layer

Transport Layer

Session Layer

Presentation Layer

Application Layer.

Physical: physically connects to two transmitters. Defines the means of communication with the transmission mechanism and the hardware item. The physical level becomes basically the cable, that enables communication and data transmission, and defines the bit stream through a channel. This treated layer electrical and mechanical concepts interface procedures well as transmission medium.

Transmission Media:

Twisted Pair: It consists of two copper wires twisted to reduce electrical interference.

Coaxial Cable: It consists of a wire inside a cylindrical conductor with better armor and can cross distances.

Fiber Optics: The light pulses bounce inside the fiber.

Data: Controls errors between two points. Validates the integrity of the data passing from one node to another controlling its flow.

The link layer is to detect and correct errors.

They contain information such as:

Number of characters: A header field stores the number, but if the number is changed, it will be very difficult to recover

Start and end characters.

Red: Routes the information through the network routing protocols Defines data to ensure that the information reaches the correct node.

Routes the packets from source to destination through intermediate routers, must know the topology of the subnet, congestion avoidance and the handle breaks if source and destination are on different networks.

Transportation: Facilitates communication between two non-adjacent points. Defines protocols for structuring messages, monitors and detects transmission errors.

Provides an efficient and reliable. The hardware and software within the transport layer are called “transport entity” may be at the heart of the operating system, a program, a card, etc.. Its services are similar to re-level as well as the addresses and flow control.

Session: Manages communication problems outside. Coordinates communications and the communication session maintains the necessary time, controlling the security, user input and administration.

Presentation: Converts the information. Define how the data is formatted, presented and coded.

Application: Provides services to applications. Defines how the application interacts with the network executed; includes database management, email and certain programs that emulate terminals.

This level is the closest to the user. Is the program or set of programs that generate information for this trip by the network, such as email, when we process and ship, this can go anywhere in the world, and r read in any computer.

8. Under Windows Networks

Configuring a peer to peer network in Windows 95/98

To configure your operating system so that we can work in a network, we must first buy the necessary wiring and installing the network card. The network card is installed like any other card that is installed in the computer. If the Plug & Play which is most common today, but we will not punch the card, restart the computer and follow the steps that the wizard. Otherwise we install the card through the wizard “Add New Hardware” located on the control panel. After installing the card can enter network configuration.

To configure the network, we must always follow the same steps:


Control panel


In the window shows the network card and an icon below marked “3Com TCAATDI”, this is what appears when installing the network card automatically unfolds.

To operate in the network, we need a physical connection, then the facility protocols. In this case be installed TCP / IP, so the configuration see

Then there are four options:

Add a client. (Installing a function will be that the operating system needs to work with Novell servers or NT servers.

Add an adapter (to add a new network card)

Add or protocol (a protocol installed)

Add a service (service installed)

Note: A customer will always need to exist protocols installed, Windows will install the necessary protocols automatically. The same goes for services, which are portions of the operating system that enable the computer to perform network functions such as file sharing, printers, etc.

MS Network Client

The next step in the configuration of the network, after the card installed, the TCP / IP, and service to share files and printers, configure the client for Microsoft Networks.

Select Client for Microsoft Networks and click “properties”

We started the session in the Windows NT domain, this option is enabled for the server to recognize us as users and offer us your services. Therefore we request a domain name the name bone gives Windows NT network.

Working Groups

To end with the general configuration of the network, we are in network properties and note the identification tab.

In this window we call our PC, also can enter a comment that will appear in the Network Neighborhood window to select our PC.

In case you do not count more than a point to point network domain concept disappears because we have no NT servers, but the whole network is given a name that is the Working Group, and all network computers must belong to the same workgroup or will not be possible to discover through the Network Neighborhood window.

In the last step if we decide to share files or printers on your computer you can specify a password for each shared item, but if you work with an NT server, this will have a list of names of users and permissions to use the network to which only have to specify which is the server domain.

9. Conclusions

Our aim is to provide the Web as a mechanism for sharing resources, so we must physically connect the computers. To do this we must choose between multiple solutions for networked computers physically connected as 10Base2 Ethernet, 10BaseT, 100BaseTX, Token Ring, etc …)

In our case we have chosen one of the most common solutions, an Ethernet 10Base T Re, this solution must install protocols that allow us communication between computers. We choose the set of TCP / IP, then installed network applications and this is achieved by installing the service to share files and printers.

The basic thing is to choose a network type, choose the protocols to use and choose the network operating system.