Equipment Used For Telephone Lines Computer Science

Essay add: 29-03-2016, 20:08   /   Views: 5

In the past years telephone lines is the only cables possibly covered the whole world. There was no other digital or analogue way of communication except this. But as technology improved more and more ways of communication introduced. Among them World Wide Web or the Internet is the largest now a days. Here in this first task we will be using the knowledge and search for new and latest technologies of telephone networking present in our own country and then establish a scenario for the company Top Web. We also have to recommend a system for them to purchase.

When more than two lines are needed, it is usual to connect them via an auncillary system capable of switching the calls to various internal extension lines. This crucial job is the basic job of a PBX machine. In the earlier stages of PBX the calls were manually switched, but now a day's calls are automatically switched by the machine itself. This tremendous facility is only possible by using a PBX machine. A typical figure of PBX machine is given below:

Figure 1.1 PBX machine and handsets

Telephone Set:

There are a variety of telephone sets available now a day in the market. Many years back the telephone sets were totally different. The dialing system was far too old. But in the latest years telephone sets has highly developed. A figure of a smart telephone set for any organization is given below:

Among the various telephone cable production companies the TAT telephone cable is the most famous in all of North Atlantic. In Canada the CANTAT is very famous. In our country the VHF and UHF microware radio links relay links are mostly used in trunk systems and some fiber optics in cities. The figure below showing telephone cable:

Figure 1.3 Telephone Cable

Facsimile Machine:

It is a device designed to convert graphical information, which can include text, contained on a sheet of paper, into a form suitable for transmission over a telecommunication link. A figure of the machine is shown below:

Figure 1.4 Facsimile Machines

The features available with each system.

The features available with each system are described below:

Private Branch Exchange:

In PBX a number of features are supported now a day, but earlier these features were not available. The features that modern PBX supports are listed below:

Call Barring

It is possible to limit the destinations to which calls may be dialed directly form an individual extension line.

Hunt Groups

This is where a group of extension lines can be accessed through a special hunt group number.

Pick up Groups

It allows each extension to answer calls for other extensions within the same pick-up group by dialing a special code.

Call Diversion

It helps by diverting the call to other extension lines or specific number of individual.

Abbreviated or short code dialing

In this feature the system is programmed to allow users to dial an abbreviated code, rather than the full number.

Enquiry Call

While involved in another call, either internal or external, this allows an extension user to make an enquiry call to another extension.

External call with someone on hold

Whilst connected to another extension, an extension user can place that extension on hold in order to make an external call.

Saved number dialed

This allows an extension user, whilst engaged on a call that they have originated, to save the number for later re-dialing.

Extension night service

This enables individual's extension to receive external calls when the system switchboard is closed.

Call parking

This allows an extension user to part a call against another extension for subsequent recovery by that extension.

Call hold

This allows an extension user to place a call on hold for 75 seconds.

Automatic call back

After the number is received or saved by the user, by using this service he can automatically call back to that number again, he doesn't have to press the number.

Conference call

By using the enquiry feature an extension user can set up a call involving either two other extensions, or one other extension and a outside user.

Communication Group

This is a group of up to 10 extension line, which can gain access to one another by dialing a two digit code.

Operator Recall

This is where the switchboard operator can be recalled into a call.

Automatic Answer

When an extension is granted automatic answer, calls to it are answered automatically.


These are the features that the Top Web organization requires and most of the features are present only in modern PBX system.

The cost of equipment and installation.Equipments NameQuantityCostPBX Machine



Telephone Set



Telephone Cable



Facsimile Machine



The cost of operating the system.

Operating name

Monthly CostYearly Cost




Telephone bill



Cable repair



Operator cost



Total Costs =



Provide a recommendation for which systems to purchase and give reasons for this recommendation:

The system that I would recommend for the Top Web organization to take is Public Branch Exchange (PBX). PBX supports the entire criterion that the organization needed and the kind of service they will require. Building an internal strong telecommunication system inside an organization is really feasible with the PBX system. There is a lot of different kind of systems available in the market, but PBX is the one that holds all the features the organization require.

The overall cost for maintaining the system for the total and year is also not that much. It is possible for organizations like Top Web to pay an amount of $7080 per year for their better service and quality. I definitely would choose PBX as my system in my organization. I strongly recommend Top Web organization to take the advantages of PBX system that we mentioned and to climb higher in their profession.


In this task we figured out the best system possible for the Top Web organization and we also recommended that in the last part. As we did the task we came close to many old and very interesting features and properties of telecommunication system. We could learn a lot about the past systems and functions.

Task Two (2)Introduction:

In this task we have to go through an investigation of the possible network topologies available in the market. We have to see all the different sides and featues of each topology possible. Then finally we will recommend the best topology for the Top Web organization. Selecting topology is not that an easy job, because the whole architecture of the organization will depend on it. So we have to be careful, and also keep space for the organization to grow in the future.

The possible network Topologies:

A topology describes the configuration of a communication network. The way in which the elements of a network are mapped or arranged is known as a network topology. The most common topologies:

Bus TopologyRing TopologyStar / Extended Star TopologyMesh TopologyTree Topology

Below the topologies are described accordingly:

Bus Topology:

The main concept of Bus topology is, it is connected with many users with only one backbone. The backbone might contain only one or more cables. All the nodes or users are connected to one main cable. And the cable contains two endpoints. It is said to be linear bus topology. Bus topology is easy to handle and implement and is best suited for small networks. But the downside of this topology is that the limited cable length limits the number of stations, thus limiting the performance to a less number of nodes. A figure representing the bus topology is given below:

Figure 2.1 Linear Bus Topology

Media: Twisted Pair /Coaxial / Fiber

Ring Topology:

A ring topology connects the computers along a single path whose ends are joined to form a circle. The data that are transmitted over the network pass through each of the nodes in the ring until they reach the destination node. In a ring network, the data and the signals that pass over the network travel in a single direction. The dual ring topology varies in having two connections between each of the network nodes. The advantage of ring topology is that the data passed between two nodes passes through all the intermediate nodes. Also a central server is not required to establish the topology.

In ring topology the disadvantages are the failure of one node or user in the ring will cause the total ring to collapse. The movement of the nodes affects the performance of the total topology. A figure of ring topology is shown below:

Figure 2.2 Ring Topology

Media: Cat 5 / Cat 6 Cable

Star / Extended Star Topology:

In star topology all the nodes are connected to a central point known as hub. All the data transmitted in this topology are transferred within the hub to the desired node. A distributed star is formed by the interconnection of two or more individual star networks. The centralized nature of a star network provides a certain amount of simplicity while also achieving isolation of each device in the network. Star topology is easy to install and maintain. If any device is connected or disconnected, no disruption of the network occurs. In this network maintenance is much easy.

Along with all the advantages there are also many disadvantages such as, it requires a lot more cables than the bus topology. It is more expensive. A figure is given below:

Figure 2.3 Star Topology

Media: Twisted Pair / Fiber, Hub or SwitchMesh Topology:

In a mesh topology, each computer on network has redundant data paths. The mesh topology provides fault tolerance-if a wire, hub, switch, or other component fails, data can travel along an alternate path. The nodes of a mesh network require possessing some kind of routing logic so that the signals and the data traveling over the network take the shortest path during each of the transmissions.

Figure 2.4 Mesh Topology

Media: Cat 5 / Cat 6 Cable

Tree Topology:

It is also known as a hierarchical topology and has a central root node that is connected to one or more nodes of a lower hierarchy. In a symmetrical hierarchy, each node in the network has a specific fixed number of nodes connected to those at a lower level. Advantages of the tree topology are it has point to point wiring for individual segment. It is supported by several hardware and software vendors.

Figure 2.5 Tree Topology

Media: Cat 5 / Cat 6 Cable

The possible Media available:

Now a day in the market there are a lot of different cables present. Among them we will try to figure out the best possible cable/media for the organization. The different criteria and the features of the cables are listed below:

Coaxial Cable

Optical Fiber Cable

The elaboration of the above cables mentioned above is described in the next page:

Coaxial Cable:

This is a type of cable that uses a center conductor, wrapped by an insulating layer and surrounded bya a braided wire mesh and an outer jacket or sheath, to carry high-bandwidth signals, such as network traffic or broadcast television frequencies. Coax is often used as a shortened form of coaxial cable. A figure is given below showing the intimate detail of the cable.

Figure 2.6 Coaxial Cable

The basic two of cable that are used as coaxial cabling is Category 5 and Category 6.

Category 5

Category 5 cable is a twisted pair high signal integrity cable type often referred to as Cat5 or Cat-5.

Category 6

Commonly referred to as Cat-6, is a cable standard for Gigabit Ethernet and other network protocols that are backward compatible with the Category 5/5e and Category 3 cable standards.

Optical Fiber Cable:

Optical fiber cable is a cable containing one or more optical fibers. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed. A figure showing the simplest optical fiber cable.

Figure 2.7 Optical fiber Cable

Recommendations for the Top Web:

I recommend the Top Web organization to choose Extended Star Topology and to use CAT 6 coaxial cable. The reason I choose these are: The installation is much easier then the mesh topology and also cheap then that. It requires less cable then mesh topology. If the organization use star topology then it would be easier for them to maintain the network. For all these reasons I definitely would recommend extended star topology with category 6 coaxial cabling.


As the task ends our idea about the topologies and the media increased a lot. We went deep enough to have a better understanding of these facts for the organization. I hope we choose the right thing and recommended the best possible solutions for the organizations.

Task Three (3)Introduction:

In this task we will go through a practical investigation for determining the cost and the equipment needed for establishing the intranet for the organization. We also have to keep the scope for the extranet too. Below I try to clarify these facts as possible.

To host the intranet for the organization:

These are the basic components required to set up the intranet for the organization. Without these seven components intranet would not be possible to set up. The components are listed below:

21 Computers with high configuration


Mail Server

Web Server


Printer/Fax machine

Internet Connection

The cost that would require setting up the intranet is given in a table below:

HardwareCost ($)

Cost (Taka)

21 PC's






Mail server



Web Server






To run the intranet in the organization the cost that might require monthly and yearly are given below in a table:

RunningCost ($)-per month

Cost (Taka)-per month

21 Computers






Mail Server



Web Server









The hardware that will be required to run the intranet also requires some cost monthly and yearly. The cost of maintaining hardware is given below in a table:

RunningCost ($)-per monthCost (Taka)-per month

21 Computers



Mail Server



Web Server






Network Tools






These are the basic costs that the organization have to go through.

Extending Intranet to Extranet:

The organization now needs to extend its intranet to connect itself to the extranet. This connection process is simply shown by the diagram below:

Figure 2.8 Extending Intranet to Extranet

Setting up the extranet connection:

Through extranet a business shares confidential information. Through extranet we can share information in such ways which other media can not. It is unfortunate that complex and expensive content management issues have made it unrealistic for many companies to effectively utilize extranets. In our case as we have to use extranet, we definitely have to use a secure way for the organizations communication. The intranet that we set up previously should be connected with an ISP for getting extranet facilities. The client page can be accessed by anyone in the organization who needs to review and have input into the project. Client pages can be accessed from anywhere in the world at any time. For this we need a high bandwidth from the ISP. We also need a strong authentication process.

Storage features of Electronic files for the organization:

Beside all these the Top Web organization will also provide mail service to its clients and staffs. A good amount of storage is required in the mail server. The configuration of the mail server is given below:

Hard drive - 500 GB, should have options to extend in future.

Mail filtering support facilities.

Robust Email Security Support.

Virus protection Mandatory

Mailing list

Support SMTP, LADP, POP3 ports and a lot more.

Hassle-free migration

Advanced Emailing support

Along with Mail Server, the company will also have a Web Server. The features of web servers of these companies are-

Hard disk - 1 TB and should be able to extend.

Strong structural support

Virtual hosting capabilities

Large file transfer support

Server scripting support

Easy access facilities

Have to be dynamic

With suitable application

Domain Name system

Recommendations for how intranet, extranet and the storage should be maintained:

At first for the intranet, the intranet is specially set up for only the company's internal address. This will be used by the company's employees only. For setting up the intranet we used computers, switches, web server, mail server and an internet connection from the ISP and suitable cables for the intranet. Secondly we will extend this intranet to extranet. For making the network become extranet we need a high bandwidth connection internet connection from the ISP. By making the network also connect to extranet the employees can now use the network even form outside of the office. This will let them become more flexible at their work. For all these the Web Server and the Mail Server needed a big and enough storage space and which we recommended on the above sections are adequate for the timing.


By doing this task we gained a lot of knowledge about Web and Mail server. Making a whole organization so much flexible and efficient was really a tough job to do. The critical got easy for our course coordinator. He guided us in many different ways for which we could solve the task.

Task Four (4)Introduction:

In this task we are about to go through the internet services available in my country. Among them we have to choose the best and the most suitable internet service provided. We searched in the internet and also we collected information locally and then the information are investigated and decided to meet the best service possible.

Internet Service that may be required:

In the organization Top Web, a lot of different category of sevicses are required. The employees are divided accordingly the quality of service should also be divided equally. The table represents the total overall internet service that is required for the organization.



Project manager

512 kbps

Graphic Designer

128 kbps

Web Designer

512 kbps

Web programmer

128 kbps

Sales Assignment

256 kbps

Clerical assignment

128 kbps


For 1st three person

Video conferencing


For all of the employee and client

Mail server

The connection speed suitable for the requirements:

For the organization to have the best overall performance we took almost the best internet service from the ISP. For both of the server we allocated 1 MP of bandwidth and for the employees the allocation of the bandwidth is shown above. With this much of bandwidth allocated, there should be no problem for the employees to have video conferencing and files sharing. Users existing outside of the company can also access the servers easily. In the future when the company expands we have to extend our bandwidth requirements.

Examples of Internet Service Provider (ISP) in our country:

Among many ISP available now a days in our country. It gets typically tough to select the best ISP in terms of service and quality. But a list of popular and well known ISP is listed below:

BOL (Bangladesh Online Limited) -

Business Solution.

Corporate Network Solution.

Web Domain registration and Hosting.


Wireless Broadband.

Dial-up connection.

Web Hosting and Developing.

Bijoy Online -

Web Hosting.

Network Solution.

Domain Registration.

Data communication services.

Training of Web development.

BTCL (Bangladesh Telecommunication Limited) -

Dial-up connection

Broadband Connection

Web Hosting.

Software Support.

Real Time Communication.

Aftab IT -

Broadband connection.

Wireless broadband.

VPN solution

Software and Network solution.


Broad connection

Dial-up connection

Software and web development

Domain registration

Web hosting

Real time communication

Recommendation for the particular ISP that is suitable:

According to me the ISP known as BTCL (Bangladesh Telecommunication Limited) is the best for the Top Web organization. It is the largest and the mother ISP in Bangladesh. As BTCL provide telecommunication through out the country so it would be better if we take the internet service form them. BTCL has the largest telecom infrastructure comprising of copper cabling, microwave links, satellite links, optical fiber networks etc. The service and the cost of the services are given below:


Broadband connection over ADSL technology.

Dial-up Internet

Web and DNS hosting service

.bd domain service

Prepaid telephony

Prepaid service

PSTN network over hole country

Web mail service


Registration Fee (Non-Refundable): Tk. 20,000 (USD 285)

64 Kbps & 128 Kbps Tk. 84,000 (USD 1200)

192 Kbps to 1024Kbps Tk.126, 000 (USD 1800)

Above 1 Mbps Tk. 231,000 (USD 3300)


After completing this task we could know about our own ISP present in our country. This was very helpful and informative for us. The task will also help us to take a lot of decisions in the future. We are looking forward to the next task.

Task Five (5)Introduction:

In this task we are about to write a professional report about all the tasks we did. This will help us in many ways in future. I hope to do the task as good as I can.


Article name: Equipment Used For Telephone Lines Computer Science essay, research paper, dissertation