thesis datacom final

8/8/2019 Thesis Datacom Final

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ACKNOWLEDGEMENT

I would like to acknowledgement with the sincere and warmest

gratitude to all the person who had extended their full support and

assistance to make this research possible.

To my family for the continues financial and moral support and

the love they have shown all trough out my life.

To my professor, ENGR. EPIFANIO TORRES for all the advice,

guidance and patience in teaching us.

To all the staff of EDP New Exec Bldg. Mandaluyong City Hall

Engineering Department for allowing me to propose a LAN design to

their office.

Above all to all mighty GOD whos been with me every single

moment of my life. For giving me a healthy body and healthy mind and

a healthy spirit that help me finished the research.


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CHAPTER Iy Introductiony Background of the Study

y Objectives

y Significance of the Study

y State of the Problem

y Scope and the Delimitation of the Study

y Conceptual and Framework

y Definition of Terms


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The advent of personal computers changed the type of information sent

over office computer networks. Terminals were no longer "dumb," but

contained the power to perform their own instructions and maintain their

own memories. This took considerable pressure off mainframe devices,

whose energies could now be devoted to more complex tasks.

LANs allowed for the transmission of data between workers. In turn,

they enabled this shared data to be directed to a common printer,

serving a larger group of users. This eliminated the need for each

worker to have a printer and ensured that the one printer provided was

not underutilized. In addition, LANs allowed data to be called up directly

on other workers' computers, providing immediate communication and

eliminating the need for paper. The most common application was in

interoffice communications, or electronic mail (e-mail). Messages could

be directed to one or several people and copied to several more over

the LAN. As a result, an e-mail system became something of an official

record of communications between workers. Addressees became

obligated to respond to e-mail messages in a timely manner because

their failure to answer could be easily documented for supervisors.


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BACKGROUND OF THE STUDY

A Local Area Network (LAN) is a group of computers and

associated devices that share a common communications line or

wireless link. Typically, connected devices share the resources

of a single processor or server within a small geographic area (for

example, within an office building). A local area network may serve as

few as two or three users (for example, in a home network) or as many

as thousands of users (for example, in an FDDI network).

As larger universities and research labs obtained more

computers during the late 1960s, there was an increasing pressure to

provide high-speed interconnections. A report in 1970 from the

Lawrence Radiation Laboratory detailing the growth of their "Octopus"

network gives a good indication of the situation. Cambridge Ring was

developed at Cambridge University in 1974 but was never developed

into a successful commercial product. Ethernet was developed at Xerox

PARC in 19731975, and filed as U.S. Patent 4,063,220. In 1976, after

the system was deployed at PARC, Metcalfe and Boggs published their

seminal paper, "Ethernet: Distributed Packet-Switching for Local

Computer Networks


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Standards evolution

The development and proliferation of CP/M-based personal

computers from the late 1970s and then DOS-based personal

computers from 1981 meant that a single site began to have dozens or

even hundreds of computers. The initial attraction of networking these

was generally to share disk space and laser printers, which were both

very expensive at the time. There was much enthusiasm for the

concept and for several years, from about 1983 onward, computer

industry pundits would regularly declare the coming year to be the year

of the LAN. In practice, the concept was marred by proliferation of

incompatible physical Layer and network protocol implementations, and

a plethora of methods of sharing resources. Typically, each vendor

would have its own type of network card, cabling, protocol, and network

operating system. A solution appeared with the advent of Novell

NetWare which provided even-handed support for dozens of competing

card/cable types, and a much more sophisticated operating system

than most of its competitors. Netware dominated the personal computer

LAN business from early after its introduction in 1983 until the mid

1990s when Microsoft introduced Windows NT Advanced Server and

Windows for Workgroups. Of the competitors to NetWare, only Banyan


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Vines had comparable technical strengths, but Banyan never gained a

secure base. Microsoft and 3Com worked together to create a simple

network operating system which formed the base of 3Com's 3+Share,

Microsoft's LAN Manager and IBM's LAN Server - but none of these

were particularly successful. During the same period, Unix computer

workstations from vendors such as Sun Microsystems, Hewlett-

Packard, Silicon Graphics, Intergraph, NeXT and Apollo were using

TCP/IP based networking. Although this market segment is now much

reduced, the technologies developed in this area continue to be

influential on the Internet and in both Linux and Apple Mac OS X

networkingand the TCP/IP protocol has now almost completely

replaced IPX, AppleTalk, NBF, and other protocols used by the early

PC LANs.


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Cabling

Early LAN cabling had always been based on various grades of

coaxial cable, IBM's Token Ring used shielded twisted pair cabling of

their own design, and in 1984 Star LAN showed the potential of simple

Cat3 unshielded twisted pairthe same simple cable used for

telephone systems. This led to the development of 10Base-T (and its

successors) and structured cabling which is still the basis of most

commercial LANs today. In addition, fiber-optic cabling is increasingly

used in commercial applications. As cabling is not always possible

wireless is the most common technology in residential premises as the

cabling required is minimal.


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OBJECTIVES

y To be familiar with Local Area Network(LAN) as the company

must be provide

y To be share and connect workstations, personal computers,

printers, servers, and other devices

y To be able to maintain the confidentiality of data as it is stored,

processed or transmitted on a LAN

y To determine how my proposed LAN design will help the

company


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CONCEPTUAL FRAMEWORK

Finding for a potential company that is appropriate to the study.

Make a permit or permission letter to the potential company for their approval.

Went to the company and see the actual floor plan of the facility.

Analyzed and identify the existing problems of their LAN installation.

Formulate goals and objectives to be achieved.

Formulate and create a design that is cheaper and much better than their current LAN

connection.


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STATEMENT OF THE PROBLEM

LANs are susceptible to many kinds of transmission errors.

Electromagnetic interference from motors, power lines, and sources of

static, as well as shorts from corrosion, can corrupt data. Software bugs

and hardware failures can also introduce errors, as can irregularities in

wiring and connections. LANs generally compensate for these errors by

working off an uninterruptable power source, such as batteries, and

using backup software to recall most recent activity and hold unsaved

material. Some systems may be designed for redundancy, such as

keeping two file servers and alternate wiring to route around failures.

Security problems can be an issue with LANs. They can be

difficult to manage and access because the data they use is often

distributed between many different networked sources. In addition,

many times this data is stored on several different workstations and

servers. Most companies have specific LAN administrators who deal

with these issues and are responsible for the use of LAN software.

They also work to backup files and recover lost files.


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SIGNIFICANCE OF THE STUDY

One of the great attributes of a LAN is that it may be installed

simply, upgraded or expanded with little difficulty, and moved or

rearranged without disruption. LANs are also useful because they can

transmit data quickly. Perhaps most importantly, anyone familiar with

the use of a personal computer can be trained to communicate or

perform work over a LAN. But despite their great potential and

capabilities, LANs have yet to demonstrate an increase in office

productivity. They have certainly eliminated paper and speeded the flow

of information, but in many cases they have also created additional

work in terms of organization, maintenance, and trouble-shooting. It will

help the researcher to pass the subject as well as to gain information

and more knowledge about networking.

For the EDP New Exec Bldg. Mandaluyong City Hall Engineering

Department this study will improve their productivity and efficiency in

providing services to those concerned individuals. This study will make

easier to their work, especially in sharing documents.


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SCOPE AND DELIMITATION OF THE STUDY

This research consists mainly of information, documents and

architecture regarding Local Area Network design for EDP New Exec

Bldg. Mandaluyong City Hall Engineering Department, in which the

design made, is intended to. This research discusses the different

factors that influence the Local Area Network design. The researcher

concentrates in making the design for the local area network of EDP

New Exec Bldg. Mandaluyong City Hall. The design is made exclusively

for the Mandaluyong City Hall Engineering Department, application of

such design to other establishment may not compliment well with their

existing material.

The researcher is limited to making the Local Area Network Design,

other issues that may be brought up other than the design domain is

not the researchers concern. Problems that may arise from the

execution of the design, like viruses, defective computer units,

inefficient installers, and other troubles that originates from something

other than the design itself is outside the scope of the study.


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DEFINITION OF TERMS

LOCALAREA NETWORK TOPOLOGIES

Bus Network Topology

networks employing a bus topology use a common physical

connection for communication. That means the physical media is

shared between stations. When one station transmits on the bus, all

devices hear the transmission. If more than one device transmits at the

same

Ring Network Topology - is a network topology in which each node

connects to exactly two other nodes, forming a single continuous

pathway for signals through each node- a ring. Data travels from node

to node, with each node along the way handling every packet.

Because a ring topology provides only one pathway between any two

nodes, ring networks may be disrupted by the failure of a single link ]. A

node failure or cable break might isolate every node attached to the

ring.

Star Network Topology - are one of the most common computer

network topologies. In its simplest form, a star network consists of one

central switch, hub or computer, which acts as a conduit to transmit


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messages. Thus the hub and leaf nodes, and the transmission lines

between them, form a graph with the topology of a star. If the central

node is passive, the originating node must be able to tolerate the

reception of an echo of its own transmission, delayed by the two-way

transmission time plus any delay generated in the central node. An

active star network has an active central node that usually has the

means to prevent echo-related problems.

The star topology reduces the chance of network failure by connecting

all of the systems to a central node. When applied to a bus-based

network, this central hub rebroadcasts all transmissions received from

any peripheral node to all peripheral nodes on the network, sometimes

including the originating node. All peripheral nodes may thus

communicate with all others by transmitting to, and receiving from, the

central node only. The failure of a transmission line linking any

peripheral node to the central node will result in the isolation of that

peripheral node from all others, but the rest of the systems will be

unaffected.

Mesh networking is a type of networking wherein each node in the

network may act as an independent router, regardless of whether it is

connected to another network or not. It allows for continuous

connections and reconfiguration around broken or blocked paths by


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hopping from node to node until the destination is reached. A mesh

network whose nodes are all connected to each other is a fully

connected network. Mesh networks differ from other networks in that

the component parts can all connect to each other via multiple hops,

and they generally are not mobile. Mesh networks can be seen as one

type of ad hoc network. Mobile ad hoc networks (MANET) and mesh

networks are therefore closely related, but MANET also have to deal

with the problems introduced by the mobility of the nodes. Mesh

networks are self-healing: the network can still operate when one node

breaks down or a connection goes bad. As a result, the network may

typically be very reliable, as there is often more than one path between

a source and a destination in the network. Although mostly used in

wireless scenarios, this concept is also applicable to wired networks

and software interaction. The animation at the right illustrates how

wireless mesh networks can self form and self heal.

Tree topology - is a combination of the bus and the Star Topology. The

tree like structure allows you to have many servers on the network and

you can branch out the network in many ways. This is particularly

helpful for colleges, universities and schools so that each of the

branches can identify the relevant systems in their own network and yet

connect to the big network in some way.


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A Tree Structure suits best when the network is widely spread and

vastly divided into many branches. Like any other topologies, the Tree

Topology has its advantages and disadvantages. A Tree Network may

not suit small networks and it may be a waste of cable to use it for small

networks. Tree Topology has some limitations and the configuration

should suit those limitations.

LAN DEVICES

Repeater - is a physical layer device used to interconnect the media

segments of an extended network. A repeater essentially enables a

series of cable segments to be treated as a single cable. Repeaters

receive signals from one network segment and amplify, retime, and

retransmit those signals to another network segment. These actions

prevent signal deterioration caused by long cable lengths and large

numbers of connected devices. Repeaters are incapable of performing

complex filtering and other traffic processing. In addition, all electrical

signals, including electrical disturbances and other errors, are repeated

and amplified. The total number of repeaters and network segments

that can be connected is limited due to timing and other issues.

Network Hub - is a fairly unsophisticated broadcast device. Hubs do

not manage any of the traffic that comes through them, and any packet

entering any port is regenerated and broadcast out on all other ports.


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Since every packet is being sent out through all other ports, packet

collisions result which greatly impedes the smooth flow of traffic.

Hub - is a networking device, which is used to connect the two

segments of a wired network. In star topology, every computer is

directly connected with the hub. In case of any fault in the hub, the data

communication in the network computers stops. In an Ethernet-based

network a hub is a central device that is used to connect all the

computers with each other. A hub has multiple ports such as 6, 8, 16

and 24 etc. When data packets are reached at hub, they are

broadcasted to all the computers unlike a switch and only the destined

computer receives the data. When you want to connect more than

computers with each other a hub or switch is required in a local area

network. There are two types of a hub passive hub and active hub.

LAN card - network interface card or NIC is used to join the computers

in a network. A NIC card is installed in any available PCI port inside the

computer. A unique MAC (Media Control Access) address is assigned

to LAN card. A MAC address is consists of two portions manufactures

id and the card id (PROM on the network interface card holds the

addresses). LAN card operates on the physical and data link layer of

the OSI model. A LAN card usually has twisted pair, BNC and AUI

sockets where the Ethernet cables are connected.


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LAN Extender - forwards traffic between LANs transparent to higher

network-layer protocols over distances that far exceed the limitations of

standard Ethernet. A LAN, or Local Area Network, is a high-speed data

network (usually employing Ethernet technology) to connect computer

workstations, printers, servers, and other devices. The Ethernet LAN

typically serves computer users within a single organization to provide

mutual access and file sharing for all the networked computing devices.

In addition to the devices the LAN connects, additional devices are

commonly employed to increase the overall efficiency, reach and range

of the Ethernet network. Such devices include LAN extenders,

repeaters, hubs, bridges, switches, and routers. While such devices all

provide similar services, each provides a selected feature set to

address a specific issue or problem facing network administrators.

LAN Switching is a form of packet switching used in local area

networks. Switching technologies are crucial to network design, as they

allow traffic to be sent only where it is needed in most cases, using fast

and hardware-based methods.

Router - is an electronic device that interconnects two or more

computer networks, and selectively interchanges packets of data

between them. Each data packet contains address information that a

router can use to determine if the source and destination are on the


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same network, or if the data packet must be transferred from one

network to another. When multiple routers are used in a large collection

of interconnected networks, the routers exchange information about

target system addresses, so that each router can build up a table

showing the preferred paths between any two systems on the

interconnected networks. A router is a networking device whose

software and hardware are customized to the tasks of routing and

forwarding information. A router has two or more network interfaces,

which may be to different physical types of network (such as copper

cables, fiber, or wireless) or different network standards. Each network

interface is a specialized device that converts electric signals from one

form to another.

Switch - a network switch performs the same functionality in a network

as a hub except a different that switch does not broadcast the data

packets to all the computers in a network like a hub. A network switch

has multiple ports like 4, 8, 16 and 24 etc. All the computers in a wired

network are directly connected with the switch through Ethernet cable.

Switches limit the traffic to and from each port and all the devices

connected to the switch has maximum available bandwidth. Switch

doesnt provide the built-in firewall capabilities like the routers. In the

telecommunication and packet switched infrastructure switches play an


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important role. They transmit the data towards its destination based on

the IP address.

Gateway - a gateway can be hardware or software and it acts as a

bridge between two networks. A gateway is an entrance point of a

network. A gateway connects a LAN with internet. A router acts as a

gateway device in a network. In big networks, a computer server which

acts as a gateway also acts as a proxy server and a firewall server. A

gateway computer is usually attached with the router and switch.

Bridges - a bridge is a network communication device that is used to

connect two segments of a LAN that uses the same protocol. Bridge is

like a router but it doesnt analyze the data before sending. A bridge

operates at the data link layer of the OSI model and it can be used to

connect the physically different networks and the networks that use the

different protocols such as Ethernet and Token Ring.

Modems - a modem is communication device that performs two

different functions such as modulation and demodulation i.e. it converts

the digital data into analog and analog into digital. The faster types of

the modems are used by the internet such as DSL modem, cable

modem and optical modems. The features like BPS, auto answer, data


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compression, voice/data, fax capability and flash memory distinguish

one modem from the other.


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NETWORKS

a network is a series of points or nodes interconnected by

communication paths. Networks can interconnect with other networks

and contain subnetworks.

The most common topology or general configurations of networks

include the bus, star, Token Ring, and mesh topologies. Networks can

also be characterized in terms of spatial distance as local area

networks (LANs), metropolitan area networks (MANs), and wide area

networks (WANs).

Network Components:

You will all have come across the term 'Computer Networks' many

times. The chances are you know all about LANs and WANs, network

topologies, Intranets and Internet.

In order for a computer to operate on a network, there are a range of

different components that are required. As part of the OCR syllabus, you

need to be able to describe various devices and explain their role within a

network.


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Network software - Networks consist of hardware, such as servers,

Ethernet cables and wireless routers, and networking software.

Networking software differs from software applications in that the

software does not perform tasks that end-users can see in the way

word processors and spreadsheets do. Instead, networking software

operates invisibly in the background, allowing the user to access

network resources without the user even knowing the software is

operating.

Cables - is the medium through which information usually moves from

one network device to another. There are several types of cable which

are commonly used with LANs. In some cases, a network will utilize

only one type of cable, other networks will use a variety of cable types.

The type of cable chosen for a network is related to the network's

topology, protocol, and size. Understanding the characteristics of

different types of cable and how they relate to other aspects of a

network is necessary for the development of a successful network.

Connectors - on the cable are the weakest points in any network. To

help avoid problems with your network, always use the BNC connectors

that crimp.


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Typical hardware devices that may form part of a network are:

y Personal computers used as terminals

y One or more central processing units acting as dedicated files servers

or print servers

y Disk drives

y Scanners

y Printers

By scale

Computer networks may be classified according to the scale: Personal

area network (PAN), Local Area Network (LAN), Campus Area Network

(CAN), Metropolitan area network (MAN), or Wide area network (WAN).

As Ethernet

increasingly is the standard interface for networks, these distinctions

are more important to the network administrator than the user. Network

administrators may have to tune the network, to correct delay issues

and achieve the desired performance level.

By connection method

Computer networks can also be classified according to the hardware

technology that is used to connect the individual devices in the network

such as Optical fibre, Ethernet, Wireless LAN, HomePNA, or Power line

communication.


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Ethernets use physical wiring to connect devices. Often they employ

hubs, switches, bridges, and/or routers.

Wireless LAN technology is built to connect devices without wiring.

These devices use a radio frequency to connect.

By functional relationship (Network Architectures)

Computer networks may be classified according to the functional

relationships which exist between the elements of the network, e.g.,

Active Networking, Client-server and Peer-to-peer (workgroup)

architecture.

By network topology

Computer networks may be classified according to the network

topology upon which the network is based, such as Bus network, Star

network, Ring network, Mesh network, Star-bus network, Tree or

Hierarchical topology network, etc.

Network Topology signifies the way in which intelligent devices in the

network see their logical relations to one another. The use of the term

"logical" here is significant. That is, network topology is independent of

the "physical" layout of the network. Even if networked computers are

physically placed in a linear arrangement, if they are connected via a


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hub, the network has a Star topology, rather than a Bus Topology. In

this regard the visual and operational characteristics of a network are

distinct; the logical network topology is not necessarily the same as the

physical layout.

Types of networks:

Below is a list of the most common types of computer networks in order

of scale.

Personal Area Network (PAN)

A personal area network (PAN) is a computer network used for

communication among computer devices close to one person. Some

examples of devices that may be used in a PAN are printers, fax

machines, telephones, PDAs or scanners. The reach of a PAN is

typically within about 20-30 feet (approximately 6-9 metres).

Personal area networks may be wired with computer buses such as

USB[3] and FireWire. A wireless personal area network (WPAN) can

also be made possible with network technologies such as IrDA and

Bluetooth.


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Local Area Network (LAN)

A network covering a small geographic area, like a home, office, or

building. Current LANs are most likely to be based on Ethernet

technology. For example, a library will have a wired or wireless LAN for

users to interconnect local devices and to connect to the internet. All of

the PCs in the library are connected by category 5 (Cat5) cable, running

the IEEE 802.3 protocol through a system of interconnection devices

and eventually connect to the internet. The cables to the servers are on

Cat 5e enhanced cable, which will support IEEE 802.3 at 1 Gbit/s.

Typical library network, in a branching tree topology and controlled

access to resources

All interconnected devices must understand the network layer (layer 3),

because they are handling multiple subnets (the different colors). Those

inside the library, which have only 10/100 Mbit/s Ethernet connections

to the user device and a Gigabit Ethernet connection to the central

router, could be called "layer 3 switches" because they only have

Ethernet interfaces and must understand IP. It would be more correct to

call them access routers, where the router at the top is a distribution

router that connects to the Internet and academic networks' customer

access routers.


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The defining characteristics of LANs, in contrast to WANs (wide area

networks), include their higher data transfer rates, smaller geographic

range, and lack of a need for leased telecommunication lines. Current

Ethernet or other IEEE 802.3 LAN technologies operate at speeds up to

10 Gbit/s. This is the data transfer rate. IEEE has projects investigating

the standardization of 100 Gbit/s, and possibly 40 Gbit/s.

Campus Area Network (CAN)

A network that connects two or more LANs but that is limited to a

specific and contiguous geographical area such as a college campus,

industrial complex, or a military base. A CAN may be considered a type

of MAN (metropolitan area network), but is generally limited to an area

that is smaller than a typical MAN. This term is most often used to

discuss the implementation of networks for a contiguous area. This

should not be confused with a Controller Area Network

Metropolitan Area Network (MAN)

A Metropolitan Area Network is a network that connects two or more

Local Area Networks or Campus Area Networks together but does not

extend beyond the boundaries of the immediate town, city, or

metropolitan area. Multiple routers, switches & hubs are connected to

create a MAN.


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Wide Area Network (WAN)

A WAN is a data communications network that covers a relatively broad

geographic area and that often uses transmission facilities provided by

common carriers, such as telephone companies. WAN technologies

generally function at the lower three layers of the OSI reference model:

the physical layer, the data link layer, and the network layer.

Global Area Network (GAN)

Global area networks (GAN) specifications are in development by

several groups, and there is no common definition. In general, however,

a GAN is a model for supporting mobile communications across an

arbitrary number of wireless LANs, satellite coverage areas, etc. The

key challenge in mobile communications is "handing off" the user

communications from one local coverage area to the next. In IEEE

Project 802, this involves a succession of terrestrial Wireless local area

networks (WLAN).[4]

Internet work

Two or more networks or network segments connected using devices

that operate at layer 3 (the 'network' layer) of the OSI Basic Reference

Model, such as a router. Any interconnection among or between public,


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private, commercial, industrial, or governmental networks may also be

defined as an internet work.

In modern practice, the interconnected networks use the Internet

Protocol. There are at least three variants of internet work, depending

on who administers and who participates in them:

y Intranet

y Extranet

y Internet

Intranets and extranets may or may not have connections to the

Internet. If connected to the Internet, the intranet or extranet is normally

protected from being accessed from the Internet without proper

authorization. The Internet is not considered to be a part of the intranet

or extranet, although it may serve as a portal for access to portions of

an extranet.


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Intranet

An intranet is a set of interconnected networks, using the Internet

Protocol and uses IP-based tools such as web browsers and ftp tools,

that is under the control of a single administrative entity. That

administrative entity closes the intranet to the rest of the world, and

allows only specific users. Most commonly, an intranet is the internal

network of a company or other enterprise. A large intranet will typically

have its own web server to provide users with browseable information.

Extranet

An extranet is a network or internet work that is limited in scope to a

single organization or entity but which also has limited connections to

the networks of one or more other usually, but not necessarily, trusted

organizations or entities (e.g. a company's customers may be given

access to some part of its intranet creating in this way an extranet,

while at the same time the customers may not be considered 'trusted'

from a security standpoint). Technically, an extranet may also be

categorized as a CAN, MAN, WAN, or other type of network, although,

by definition, an extranet cannot consist of a single LAN; it must have at

least one connection with an external network.


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Internet

A specific internet work, consisting of a worldwide interconnection of

governmental, academic, public, and private networks based upon the

Advanced Research Projects Agency Network (ARPANET) developed

by ARPA of the U.S. Department of Defense also home to the World

Wide Web (WWW) and referred to as the 'Internet' with a capital 'I' to

distinguish it from other generic internet works.

Participants in the Internet, or their service providers, use IP Addresses

obtained from address registries that control assignments. Service

providers and large enterprises also exchange information on the

reachability of their address ranges through the Border Gateway

Protocol (BGP).

Basic Hardware Components

All networks are made up of basic hardware building blocks to

interconnect network nodes, such as Network Interface Cards (NICs),

Bridges, Hubs, Switches, and Routers. In addition, some method of

connecting these building blocks is required, usually in the form of

galvanic cable (most commonly Category 5 cable). Less common are

microwave links (as in IEEE 802.11) or optical cable ("optical fiber").


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Network Interface Cards

A network card, network adapterorNIC (network interface card) is a

piece of computer hardware designed to allow computers to

communicate over a computer network. It provides physical access to

a networking medium and often provides a low-level addressing system

through the use of MAC addresses. It allows users to connect to each

other either by using cables or wirelessly.

Repeaters

A repeater is an electronic device that receives a signal and

retransmits it at a higher level or higher power, or onto the other side of

an obstruction, so that the signal can cover longer distances without

degradation. In most twisted pair ethernet configurations, repeaters are

required for cable runs longer than 100 meters.

Hubs

A hub contains multiple ports. When a packet arrives at one port, it is

copied to all the ports of the hub. When the packets are copied, the

destination address in the frame does not change to a broadcast

address. It does this in a rudimentary way, it simply copies the data to

all of the Nodes connected to the hub.[5]


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Bridges

A network bridge connects multiple network segments at the data link

layer (layer 2) of the OSI model. Bridges do not promiscuously copy

traffic to all ports, as hubs do, but learns which MAC addresses are

reachable through specific ports. Once the bridge associates a port and

an address, it will send traffic for that address only to that port. Bridges

do send broadcasts to all ports except the one on which the broadcast

was received.

Bridges learn the association of ports and addresses by examining the

source address of frames that it sees on various ports. Once a frame

arrives through a port, its source address is stored and the bridge

assumes that MAC address is associated with that port. The first time

that a previously unknown destination address is seen, the bridge will

forward the frame to all ports other than the one on which the frame

arrived.

Bridges come in three basic types:

1. Local bridges: Directly connect local area networks (LANs)


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2. Remote bridges: Can be used to create a wide area network

(WAN) link between LANs. Remote bridges, where the

connecting link is slower than the end networks, largely have

been replaced by routers.

3. Wireless bridges: Can be used to join LANs or connect remote

stations to LANs.

Switches

A switch is a device that performs switching. Specifically, it forwards

and filters OSI layer 2 datagrams (chunk of data communication)

between ports (connected cables) based on the Mac-Addresses in the

packets.[6] This is distinct from a hub in that it only forwards the

datagrams to the ports involved in the communications rather than all

ports connected. Strictly speaking, a switch is not capable of routing

traffic based on IP address (layer 3) which is necessary for

communicating between network segments or within a large or complex

LAN. Some switches are capable of routing based on IP addresses but

are still called switches as a marketing term. A switch normally has

numerous ports with the intention that most or all of the network be


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connected directly to a switch, or another switch that is in turn

connected to a switch.[7]

Switches is a marketing term that encompasses routers and bridges, as

well as devices that may distribute traffic on load or by application

content (e.g., a Web URL identifier). Switches may operate at one or

more OSI layers, including physical, data link, network, or transport

(i.e., end-to-end). A device that operates simultaneously at more than

one of these layers is called a multilayer switch.

Overemphasizing the ill-defined term "switch" often leads to confusion

when first trying to understand networking. Many experienced network

designers and operators recommend starting with the logic of devices

dealing with only one protocol level, not all of which are covered by

OSI. Multilayer device selection is an advanced topic that may lead to

selecting particular implementations, but multilayer switching is simply

not a real-world design concept.

Routers

Routers are networking devices that forward data packets between

networks using headers and forwarding tables to determine the best

path to forward the packets. Routers work at the network layer of the

TCP/IP model or layer 3 of the OSI model. Routers also provide


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interconnectivity between like and unlike media (RFC 1812). This is

accomplished by examining the Header of a data packet, and making a

decision on the next hop to which it should be sent (RFC 1812) They

use preconfigured static routes, status of their hardware interfaces, and

routing protocols to select the best route between any two subnets. A

router is connected to at least two networks, commonly two LANs or

WANs or a LAN and its ISP's network. Some DSL and cable modems,

for home (and even office) use, have been integrated with routers to

allow multiple home/office computers to access the Internet through the

same connection. Many of these new devices also consist of wireless

access points (waps) or wireless routers to allow for IEEE 802b/g

wireless enabled devices to connect to the network without the need for

a cabled connection.

PHYSICAL COMPONENTS OF LANS

The physical properties of a LAN include network access units (or

interfaces) that connect the personal computer to the network. These

units are actually interface cards installed on computer motherboards.

Their job is to provide a connection, monitor availability of access to the

LAN, set or buffer the data transmission speed, ensure against

transmission errors and collisions, and assemble data from the LAN

into usable form for the computer.


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The next part of a LAN is the wiring, which provides the physical

connection from one computer to another, and to printers and file

servers. The properties of the wiring determine transmission speeds.

The first LANs were connected with coaxial cable, the same type used

to deliver cable television. These facilities are relatively inexpensive and

simple to attach. More importantly, they provided great bandwidth (the

system's rate of data transfer), enabling transmission speeds initially up

to 20 megabits per second.

Another type of wiring, developed in the 1980s, used ordinary twisted

wire pair (commonly used for telephones). The primary advantages of

twisted wire pair are that it is very cheap, simpler to splice than coaxial,

and is already installed in many buildings. The downside of this

simplicity is that its bandwidth is more limited.

A more recent development in LAN wiring is optical fiber cable. This

type of wiring uses thin strands of glass to transmit pulses of light

between terminals. It provides tremendous bandwidth, allowing very

high transmission speeds and because it is optical rather than

electronic, it is impervious to electromagnetic interference. Still, splicing

it can be difficult and requires a high degree of skill. The primary

application of fiber is not between terminals, but between LAN buses

(terminals) located on different floors. As a result, fiber distributed data


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interface is used mainly in building risers. Within individual floors, LAN

facilities remain coaxial or twisted wire pair.

When a physical connection cannot be made between two LANs, such

as across a street or between buildings, microwave radio may be used.

However, it is often difficult to secure frequencies for this medium.

Another alternative in this application is light transceivers, which project

a beam of light similar to fiber optic cable, but through the air rather

than over cable. These systems do not have the frequency allocation or

radiation problems associated with microwave, but they are susceptible

to interference from fog and other natural obstructions.

TRANSMISSION METHODS USED BY LANS

LANs function because their transmission capacity is greater than any

single terminal on the system. As a result, each station terminal can be

offered a certain amount of time on the LAN, like a timesharing

arrangement. To economize on this small window of opportunity,

stations organize their messages into compact packets that can be

quickly distributed. When two messages are sent simultaneously, they

could collide on the LAN causing the system to be temporarily

disrupted. Busier LANs usually utilize special software that virtually


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eliminates the problem of collisions by providing orderly, non-contention

access.

The transmission methods used on LANs are either baseband or

broadband. The baseband medium uses a high-speed digital signal

consisting of square wave DC voltage. While it is fast, it can

accommodate only one message at a time. As a result, it is suitable for

smaller networks where contention is low. It also is very simple to use,

requiring no tuning or frequency discretion circuits. This transmission

medium may be connected directly to the network access unit and is

suitable for use over twisted wire pair facilities.

By contrast, the broadband medium tunes signals to special

frequencies, much like cable television. Stations are instructed by

signaling information to tune to a specific channel to receive

information. The information within each channel on a broadband

medium may also be digital, but they are separated from other

messages by frequency. As a result, the medium generally requires

higher capacity facilities, such as coaxial cable. Suited for busier LANs,

broadband systems require the use of tuning devices in the network

access unit that can filter out all but the single channel it needs.


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THE FILE SERVER

The administrative software of the LAN resides either in a dedicated file

server; in a smaller, less busy LAN; or in a personal computer that acts

as a file server. In addition to performing as a kind of traffic controller,

the file server holds files for shared use in its hard drives, administers

applications such as the operating system, and allocates functions.

When a single computer is used as both a workstation and a file server,

response times may lag because its processors are forced to perform

several duties at once. This system will store certain files on different

computers on the LAN. As a result, if one machine is down, the entire

system may be crippled. If the system were to crash due to under

capacity, some data may be lost or corrupted.

The addition of a dedicated file server may be costly, but it provides

several advantages over a distributed system. In addition to ensuring

access even when some machines are down, its only duties are to hold

files and provide access.

OTHER LAN EQUIPMENT

LANs are generally limited in size because of the physical properties of

the network including distance, impedance, and load. Some equipment,


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such as repeaters, can extend the range of a LAN. Repeaters have no

processing ability, but simply regenerate signals that are weakened by

impedance. Other types of LAN equipment with processing ability

include gateways, which enable LANs operating dissimilar protocols to

pass information by translating it into a simpler code, such as ASCII. A

bridge works like a gateway, but instead of using an intermediate code,

it translates one protocol directly into another. A router performs

essentially the same function as a bridge, except that it administers

communications over alternate paths. Gateways, bridges, and routers

can act as repeaters, boosting signals over greater distances. They

also enable separate LANs located in different buildings to

communicate with each other.

The connection of two or more LANs over any distance is referred to as

a wide area network (WAN). WANs require the use of special software

programs in the operating system to enable dial-up connections that

may be performed by a telephone lines or radio waves. In some cases,

separate LANs located in different citiesand even separate

countriesmay be linked over the public network.


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CHAPTERIII

y Instrumentation

y Validation process

y Treatment of data


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SOURCES OF DATA

INTERNET

BOOKS

INSTRUMENTS AND TOOLS USED

INTERVIEW - The researcher conducted a personal interview with the

employees of Engineering department and I.T department of Mandaluyong

City Hall to gather information about the LAN design of their office and what

changes do they to do to their department.

OBSERVATION - The researcher conducted observation about their office

facilities and area. Also, the activities of the employees in engineering office

are observed in order to know how the LAN will be designed.

INTERNET RESEACH - The researcher used the internet to gathered more

information about constructing local area network and n order to have general

and specific concepts about the construction of the LAN design, it is necessary

to use the internet because of its comprehensive and broad contents that are

maybe useful for the researcher to based the design.


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DATAGATHERING PROCEDURE

The researcher initially used the world-wide-web by analyzing and evaluating

the data and articles published on-line by the Google and Wikipedia (on-line

encyclopedia) and other possible resources. After data gathering and

analyzing the information, the researcher sent a request letter to the Office of

the Mandaluyong city hall, then in the EDP I.T. division office tagged it as

received and they scheduled the researcher to go back the next day for the

personal interview with the employee of the Mandaluyong city hall engineering

office. They also allowed the researcher to conduct observation to their

facilities. After the interviews and observations, the researcher requested the

floor plan of EDP engineering office . The employee from EDP engineering

office produced a photo copy of the floor plan. The researcher analyzes

studied the floor plan and started designing the possible LAN design using

MicrosoftVisio.


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CHAPTERV

y Summary

y Conclusion

y Recommendation


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SUMMARY

Communication channels and hardware may have different lay-outs or

networks, ranging size from large to small: Wide area networks, metropolitan

area network, and local area network. A network or communication network is

a system of interconnected computers, telephones, and other communications

devices that can communicate with another and share applications and data.

Actually, there are some types of networks but this study focused only in LAN.

LAN may be client-server or peer-to-peer network and include components

such as cabling, networks interface cards, network operating system, other

shared devices and bridges and gateways. The topology, or shape, of a LAN

may be: star, ring, bus, mesh and tree. In the LAN design of EDP engineering

office, all basic concepts about LAN were studied and analyzed first

particularly the specifications of components to be used and applied in LAN.

After studying the EDP engineering office area and facilities, all facts

were arranged logically before formulating the solutions. It may be recalled

that there were problems raised at the introductory part.

Consequently, the researcher laid-out the design based upon the floor

plan of EDP engineering office. After lay-outing and designing was

established, the hardware and software to be purchased are canvassed and

quoted in by three suppliers so that the researcher can chose among of them

is affordable and advisable to deal with. After presenting the design, all


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findings were discussed and explained before to and recommend to interested

sectors.

CONCLUSION

By this time in the midst of the recent improvement of technology, it is

the best way to have the advantage of network. With a network, a user must

explicitly log onto move files around and generally handle all the network

management personally. With a distributed system nothing has to be done

explicitly, it is all automatically done by the system without the users

knowledge. From the research study conducted, I conclude that an efficient

and flexible Local Area Network (LAN) would be a save to resources for it will

minimize expenses, workstations well be connected, users will be working

efficiently and the work output is great.

RECOMMENDATION

Every layer or workstations have a mechanism for connection

established. Since a network normally has many computers, some which

have multiple process one peripheral to specify with whom it wants to

established a connection. As consequences having a multiple destinations,

some form of addressing is needed to order of specific a destination. Closely

related the peripherals for establishing connections, across the network are

peripherals for terminating them once they are no longer needed. Not all


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communication channels preserve the order of message sent on them. To

deal of the possible loss of sequencing, the protocol must have explicit

provision for the receiver to allow the pieces to back together properly. An

obvious solution is to number pieces, but his solution still leave open the

question of what be done with pieces that arrive out of order.


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CHAPTERIV

y DIMENSIONING

y COMPANY DESIGN (FLOOR PLAN)

y NETWORKING DESIGN

y PROPOSED DESIGN

y DISCUSSION OF PROPOSED DESIGN


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LOCALAREA NETWORK (LAN)

A Reseach Paper Presented to

ENGINEER EPIFANIO TORRES

Coe Department Head

Eulogio Amang Rodriguez

Institute of Science and Technology

In Partial Fulfillment of the

Requirements forApplied Research

Poliquit, Jinnon G.

1


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TABLE OF CONTENTS

Title page i

Preface ii

Acknowledgment

Table of contents iv

CHAPTER I

THE PROBLEM AND ITS BACKGROUND

INTRODUCTION 1

BACKGROUND OF THE STUDY 4

OBJECTIVES . 7

CONCEPTUAL FRAMEWORK .. 8

STATEMENT OF THE PROBLEM 9

SIGNIFICANCE OF THE STUDY 10

SCOPE AND DELIMITATION OF THE STUDY.. 11

DEFINITION OF TERMS. 12

CHAPTER II

REVIES OF RELATED LITERATURE 21

CHAPTER III

SOURCES OF DATA .40

INSTRUMENTS AND TOOLS USED 40

DATA GATHERING PROCEDURE. 41

CHAPTER IV

DIMENSIONING i

COMPANY DESIGN (FLOOR PLAN).. ii

NETWORKING DESIGN iii


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PROPOSED DESIGN iv

DISCUSSION OF PROPOSED DESIGN 42

COMPANY PROFILE 43

CHAPTER V

SUMMARY 44

CONCLUSION 45

RECOMMENDATION... 46


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PREFACE

Local Area Network is now taking over a big part on different

companies. As a big solution to what previously tons of paperwork,

calls, records and files, and some other related office works is now

easily manageable and flexible.

From the traditional approach of manual encoding by computer

assistance, the designer proposed a Local Area Network especially

created and designed for the needs and requirements of Division Office

of Quezon City, for the company acquiring a reliable technology in

demand for the company as of now.

thesis datacom final

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