Enterprise networking Essay

I would wish to admit the parts and attempt that has been provided by our lector Mr.Sarwar Hossain Mollah who have worked really difficult to do this Internet Security assignment easy for us to understand. I am besides really thankful to him for assisting me to understand and complete this equivocal assignment without any jobs.

This assignment was a great pleasance and chance to us, which helped us to spread out our cognition and accomplishments in Security. We esteem the illustriousness of NCC and thank NCC for giving us such a fantastic chance to better our accomplishments. Thankss to NCC one time once more for supplying this planetary IT instruction installation to the pupils universe for which we are geting better instruction.

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I would wish to thank my parents for there changeless inspiration and encouragement to consummate this assignment. Thankss to other employees of Daffodil Institute of Information Technology particularly to my fellow friends and schoolmates who helped me with their changeless aid.

Finally, I thank ALLAH who spiritually helped me and gives me strength to vie.

Task-1

  1. Topology of a web refers the logical and physical connexion between nodes ( workstations ) . Logical Topology explains how the information transportation is traveling to take topographic point while the Physical Topology is concerned with how the nodes are traveling to be connected by agencies of wires, overseas telegrams or other medium.
  2. Basically, there are two types of logical topology:

  • Bus
  • Ringing

Physical Topology of a web can be star or mesh or something else but its logical topology has to be anyone of Bus or Ring.

Bus Topology:

Bus webs uses a common anchor to link all devices. A individual overseas telegram, the anchor maps as a shared communicating medium that devices attach or tap into with an interface connection. A device desiring to pass on with another device on the web sends a broadcast message onto the wire that all other devices hear, but merely the intended receiver really accepts and processes the message ( Network Topologies ) . At the terminals of the coach attached are Exterminators which device terminates any signal that has been left unattended and occupies the anchor forestalling the transportation of other signals. But there are ever high chance of hits in coachs which can be avoided by CSMA/CD.

Ring ;

In a ring web, every device has precisely two neighbours for communicating intents. A particular form of spots revolves around the ring called the Token. A node in the web can merely convey informations when it recieves the Token. It attaches the information to the Token with the finish reference and so sends it. After recival a verification is given to the transmitter. All messages travel through a ring in the same way either clockwise or counterclockwise. A failure in any overseas telegram or device breaks the cringle and can take down the full web. But this job can be avoided to an extent when Dual Ring is adhered.

  • Suitable media types available for organizing the web are:
    1. Unshielded Distorted Pair ( UTP ) Cables.
    • Class 5e
    • Class 6
    • Class 7
    • Optical Fibre Cable.
  • Wireless Communication.
    • Radio.
    • Microwave.
    • Infrared.

    Unshielded Distorted Pair ( UTP ) Cables:

    Advantages of UTP Cable:

    • Less expensive and comparably efficient.
    • Available.
    • Easy to put in.
    • Many classs to take from.

    Disadvantages of UTP Cables:

    • High Cost maintainence.
    • Susceptible to corrison rapidly.
    • Probability of being larceny.
    • Vulnerable to crosstalk and resound.

    Optical Fibre Cable:

    Advantages of Optical Fibers:

    • It provides a higher transmittal capacity.
    • It provides wide bandwidth.
    • It is easy movable.
    • Immune to electromagnetic intervention.
    • Capacity to convey all signifiers of communicating ( voice, informations and picture ) .

    Disadvantages of Optical Fibers:

    • Used merely in peculiar fortunes.
    • Very expensive.
    • Fragile than other sorts of overseas telegrams.

    Radio:

    Advantages of Wireless Transmission:

    • Workstations can be added easy.
    • Workstations can be nomadic.
    • Installation less hard.
    • Environment remains orderly and clean due to no wires.

    Disadvantages of Wireless Transmission:

    • Lower bandwidth due to restrictions of signals.
    • Costss more than wired devices.
    • High chance of intervention occuring.
    • Many security menace deductions.
  • For logical topology Dual Ring would be best suited because the opportunities of hits will be decreased greatly and for physical topology, Extended Star will be applicable because there will be multiple worstations connected from multiple sites and it will besides guarantee reliablity in instance of a node dislocation. The lone medium suited for the web would be a class of UTP Cable and it should be Category 7 because it is shielded and immune to crosstalk or resound. Optical Fibers will be overhead because the communicating is in-house. Wireless transmittal can non be implemented because there will be many gaps to information larceny and protecting the signals will add more cost to the budget.
  • Task-2

    1. Based on what topology and medium type has been chosen antecedently, Broadband Internet Service will be best suited for a Police Department because Broadband Service provides really high velocity informations transportation rates. Broadband services are available in half and full semidetached house communications. For this sort of organisation, Full Duplex communicating is best suited so that, incoming transmittal does non impede surpassing transmittals. Broadband services besides allows for many picks of transmittal rates as needed ranging from ~1Mbit/s to ~160Gb/Bits. The braodband service can be undependable at times but if a really sure ISP is chosen for the service and dedicated service is chosen so there will non be any room for via media.
    2. Connection velocity suitable would be 55 MB/s.
    3. The ISPs supplying best of services and dependable are as follows:
    • BDCOM Online Ltd.
    • Link3 Technologies.
    • IS PROS Limited.
  • Harmonizing to the ratio of monetary value to service. Link3 has a really good repute. Therefore, Link3 should be chosen. Their bundle is as follows:
  • Package: Broadband ( Dedicated ) – 1MB/s*55=55 MB/s.

    Monthly Charge: 55 MB/s*18,000 BDT= 9,90,000 BDT.

    Task-3

    1. The method for Two-way voice communications available is PTMR ( Private Trunked Mobile Radio ) .
    2. Its characterstics are as follows:

    • Point to multi-point communications ( as opposed to cell phones which are point to indicate communications ) .
    • Push to speak, release to listen – a individual button imperativeness opens communicating on a wireless frequence channel.
    • Large coverage countries.
    • Closed user groups.
    • Communication on a individual channel ( half semidetached house ) .
    • Use of VHF or UHF frequence sets.
    • Requires license from govermental section.
    • Bandwidth and channel handiness limited.

    In general narrow set frequence transition is the chosen signifier of transition for PTMR. Typically a divergence of 25kHz is used for FM and this enables a channel spacing of 12.5kHz to be implemented. As the demands for PTMR are high, it is necessary to do effectual usage of the channels available. This is achieved by re-using the frequences in different countries. Base Stationss must be located sufficiently far apart so that intervention is non experienced ( Professional Mobile Radio ) .

  • Licensing Gudelines:
    1. The Licensee shall set up, run and keep the BWA Services every bit provided in the License.
    2. In order to guarantee proper competition among the BWA Services licensees, entire 3 ( three ) licences will be issued to supply countrywide BWA Services in 2.3 GHz and 2.5 GHz spectrum sets. An extra BWA licence ( 4th licence ) may be issued to Bangladesh Telecommunications Company Limited ( BTCL ) in the same footings and conditions including the License Acquisition Fee ( to be fixed by manner of auction ) as shall be applicable to the other BWA licensees.
    3. Two licences will be awarded to the prospective Applicant ( s ) to supply countrywide BWA.
    4. Servicess in 2.3 GHz and one licence will be awarded in 2.5 GHz spectrum sets.

    5. The continuance of the Licenses, shall ab initio be for a term of 15 ( 15 ) old ages. Upon termination of the initial term, the License may be renewed for subsequent footings, each of 5 old ages in continuance, capable to the blessing from the Commission and to such conditions, including the payment of any fees, as may be specified herein and/or by the Commission under the Act.

  • Frequency Distribution:
    1. Spectrum bands 2.3 GHz and 2.5 GHz have been considered for BWA Service License.
    2. A immediate 30 MHz of odd spectrum from 2.3 GHz set ( 23xx-23xx MHz and 23xx-23xx MHz ) will be assigned to 2 licensees. ( Licensing Guidelines ) .
    3. A immediate 30 MHz of odd spectrum from 2.5 GHz set ( 25xx-26xx MHz ) will be assigned to 1 licensee. 2615-2620 MHz is kept as guard block between TDD and future FDD assignment.
    4. 30MHz immediate channel will be allocated to each operator to supply BWA services. Per channel bandwidth should be either 5 or 10 MHz.
    5. The spectrum assignment will be inclusive of guard sets needed for the operation of the equipments to avoid doing harmful intervention to next equipments runing in next sets. No separate spectrum shall be kept as guard set between two assignments in 2.3 GHz set. ( Licensing Guidelines ) .

  • Fees and Charges:
  • The spectrum charges shall be calculated utilizing the undermentioned expression:

    Spectrum Charges in Taka = STU x CF x BW x AF x BF.

    Where, STU=Spectrum Tariff Unit=Tk. 60.00 per MHz per Sq.km.

    CF=Contribution Factor.

    BW=Bandwidth Assigned for Access Frequency in MHz.

    AF=Area Factor for Access Frequency=147570 Sqkm.

    BF=Band Factor.

  • Restrictions:
  • The operators, within 1 twelvemonth of issue of licence, shall hold to put in minimal 5 full fledged Base Station Transceiver ( BTS ) wireless sites in countries covering each Divisional Headquarters and 3 BTS covering each District.

    Frequency Scope: 2.3 Ghz – 2.5Ghz.

    Frequency Limitaion: 25 Km radius.

    Signing: 5-Tone Advanced Signalling.

    Channel Spacing: 12.5 Khz.

    Intervention: Co-channel Interference, Adjacent Channel Interference and Intermodulation ( Operating frequence scope explained, 2008 ) .

  • To implement PTMR a web of Stationss are set up.
  • These Stationss are linked by and large utilizing land lines, although optical fibres and point to indicate wireless are besides used. In this manner the different base Stationss are able to pass on with each other. PTMR besides allows figure of users to portion a set of frequence which is done by Radio Trunking. A Trunked wireless system makes usage of several wireless channels centrally managed by a Trunked Controller to supply communicating between wireless users. When a user makes a call, the Trunked Controller automatically allocates a free channel and sends a message to the wireless units involved in the call teaching them to alter to the free channel. This means that a conversation can be made if any channel is available. Since the communicating between the wirelesss traveling on will be sensetive, Encryption is required to protect information being leaked by the usage of Scanners. Encryption modifies a voice signal utilizing a cryptography algorithm. An encoding key controls this algorithm. The encoding key is used by the transmiter and receiving system wireless to enable the voice signal to be coded and decoded for both wireless. Therefore, all wirelesss pass oning must hold fiting encoding keys, or encoding will non work ( PMR – Private Mobile Radio FAQ ‘s ) .

    If more scope is to covered than the frequence coverage can be increased by the usage of repeaters. A repeater can be a utile tool to increase the operating scope of a wireless system. With its comparatively high conveying power & A ; external aerial, a well-sited repeater will supply an first-class platform to hike signals beyond the scope of non-repeater webs. Whether it is sited at the Centre of operating web or at a location prone to weak coverage, the repeater will outright re-transmit standard sound without any noticeable hold ( Repeater applications explained! ) .

    The above recommendation has been given due to many advantages explained in other Undertakings but as an overview will be briefed below as the advantages of implementing the:

    PTMR communications system:

    • Improved communicating and affair between users.
    • Increased intelligence exchange.
    • Increased safety and assurance for users.
    • A more effectual early warning system enabling the users to supply a more pro-active attack.
    • Support and backup.
    • Crime disincentive, public safety and improved assurance for them.
    • Greater cognition of felons, particularly for retail secret agent.
    • Quicker responses.

    Task-4:

    1. The organisation investigated was a Computer Gross saless Plaza called IDB.
    2. The Adminstration section of IDB has a Hosted PBX ( Private Branch Exchange ) installed from BRTC. Every store in IDB is connected through the Adsminstration office so that calls can be routed to specific stores. Since it is a hosted PBX, all the equipments are in BRTC ‘s premises. So the undermentioned names of equipments are based on premises and mentions.

      The equipments more or less required are:

    • The PBX ‘s internal shift web.
    • Microcontrolleror microcomputerfor arbitrary informations processing, control and logic.
    • Logic cards, exchanging and control cards, power cards and related devices that facilitate PBX operation.
    • Stations or telephone sets.
    • Outside Telco short pantss that deliver signals to ( and carry them from ) the PBX.
    • Console or patchboard allows the operator to command incoming calls.
    • Uninterruptible Power Supply ( UPS ) dwelling of detectors, power switches andbatteries.
    • Complecting wiring.
    • The PBX features the undermentioned characteristics from mail to optional 1s:

    Main:

    • Establishing connexion between two telephone sets of two users.
    • Keeping connexions every bit long as user requires.
    • Dial outside lines.
    • To do an extension question while connected to and on clasp another external call.
    • Transfer an external call to the extension that has been enquired.

    Extra:

    • Auto-attendant.
    • Calls are answered automatically by a pre-recorded message or a bill of fare system.

    • Automated directory services.
    • Where companies can be routed to a given employee by identifying or talking the letters of the employee ‘s name.

    • Call Diversion.
    • Calls will be diverted to an extension when a given status will be fulfilled.

    • Saved Number Dialled.
    • Allows to salvage an incoming figure and re-dial it at a ulterior clip.

    • Call park.
    • A characteristic of sometelephone systemsthat allows a individual to set a call on clasp at one telephone set and go on the conversation from any other telephone set.

    • Hunt Groups.
    • If one extension is busy so the call will be routed to the available extension in the Hunt Group figure.

  • Since the organisation is utilizing a Hosted PBX. They have disclosed the undermentioned costs.
  • The hardware and apparatus cost included = 1,30,000 BDT/Month.

  • If something goes incorrect with the telephone sets or wiring in the user premesis so the users has to face the costs. Their monthly cost on PBX requires as follows:
  • Replacing amendss sets= 2,850 BDT/Telephone set.

    Wiring Replacement= 25 BDT/Feet of wire.

    Any harm occuring at the supplier premesis is maintained by them.

  • The Hosted PBX is the best solution for any organisation can afford. Because most of the jobs are handled by the supplier including any necessary cost ( varies with supplier ) . Other advantages of PBX are detailed below:
    1. It allows all employees to portion phone system lines, therefore cut downing overall telecommunication disbursals.
    2. The PBX system is wholly programmable and can back up complex installing or integrating demands.
    3. There are a broad assortment of standard, every bit good as extra characteristics with the PBX system.
    4. The PBX system is easy expandible as the organisation grows.
    5. The physical PBX hub is low profile and does non necessitate a big sum of infinite.
    6. Installing PBX may necessitate investing of a large sum but on the long tally, it is profitable.
    7. Save money with no PBX hardware to buy or rent and no labour or care of all time needed
    8. PBX provides the best sounding telephone conversations with digitally optimized voice managing

    Due to all the above advantages over other telecommunication options. It is recommended that Hosted PBX be used and if possible better supplier and more characteristics be adhered to.

    Task-5:

    Executive Summary:

    This study will be consisted of the followers:

    1. Topology that will be suited for the Police Department Networking.
    • Which Physical and Logical Topolgy.
    • Advantages and Disadvantages of the medium.
    • ecommendation for a Topology and its associated medium.
  • Internet Connection Requirements for the Police Department.
    • Type of Internet Service.
    • Bandwidth most suited.
    • Supplying ISPs available and the associated costs.
    • Recommendation of an ISP.
  • A Bipartisan voice communicating method that can be implemented.
    • Possible voice communicating methods.
    • Legislation.
    • Costss and charges.
    • Restrictions and coverage.
  • Recommendation for Telephone Systems to be purchased.
  • Equipments required with related system.
  • Features available with system.
  • Cost of equipment, installing and maintainence.
  • Recommendation for a Telecommunication system.
  • Introduction:

    The digest of this undertakings forms an end product which will supply a whole web construction required to run big single-site organisations such as The Police Department. Since, imlementing such large web gets governmental, legal demands are besides required which have besides been mentioned.

    Topology that will be suited for the Police Department Networking:

    To propose a topology for the Police section, information about the topologies are besides required. But before that, What is a Topology? Topology of a web refers the logical and physical connexion between nodes ( workstations ) . Logical Topology explains how the information transportation is traveling to take topographic point while the Physical Topology is concerned with how the nodes are traveling to be connected by agencies of wires, overseas telegrams or other medium. Why a Topology is required for the web? A topology is required because it gives the web an architecture or a construction to follow which will house the communications between the nodes and on the web. After a done analysis, it has been recommended that a logical ring implemented as a physical star ( extended ) be adopted. Because pealing topology compared to bus has many advantages and reduces the cost of keeping equipments which increases the efficiency of the web like CSMA/CD used in coach topologies. Physical star will be most suited because there will be multiple sites connected to a waiter. If star is adopted so multiple sites can be connected with the aid of hub/switch to organize a centralised construction to the waiter.

    Internet Connection Requirements for the Police Department:

    Internet is required by any official sections. So, The Police Departments requires one excessively. Now, it might acquire really confounding about what Internet Service will be most suited for the section. To contract the hunt, concentration be put into the demands of bandwidth and consumers. Since there are great figure of bandwidth consumers, whose list will be provided below:

    Wrok Stationss in each office in each territory ( x4 ) :

    District Commander= 1

    Deputy District Commander= 1

    Seargents= 1

    Constables= 5

    Detective Squad=21

    Total= ( 1+1+1+5 ) ten ( 4 ) +21= 53 Workstations required

    Therefore, 76 Workstations entire in 4 Districts.

    Assuming that all of the wokstations more or less is traveling to be active, high abdnwidth is required. Therefore, it is suggested that Broadband Internet Services be implemeted with the high bandwidth bundle the ISPs has to offer. The connexion velocity for this large of an organisation as a whole should be from 50 MB/s to 55 MB/s. Calculation will be done to minimum because ISP suppliers vary from topographic point to topographic point and their related charges. Harmonizing to the ratio of monetary value to service provided. Link3 has a really good repute. Therefore, Link3 should be chosen. Their bundle is as follows:

    Package: Broadband ( Dedicated ) – 1MB/s*55=55 MB/s.

    Monthly Charge: 55 MB/s*18,000 BDT= 9,90,000 BDT.

    A Bipartisan voice communicating method that can be implemented:

    There are many methods through which bipartisan communicating could be achieved. They are PTMR, cellular Radio, MPDN and etc. But the system that is popular and implementable is the PTMR ( Private Trunked Mobile Radio ) . PTMR has been used and is still being used by many Police forces around the Earth. Therefore, it is perfect for the Townsville Police Department besides. This method consists of Radio Devices which can be used to make both speaking and hearing though the communicating is half-duplex that is why usage of phrases such as ‘over and out ‘ is indispensable. Every police officer will be transporting one of the wireless devices and base Stationss will be set up in the territory offices and the central office. Use of repeaters can besides be implemeted if signals are distorted. Repeaters can increase the radius of signals therefore, covering more distance. Encoding is encouraged because Police conversation is really of import and sensetive so, its leak can make mayhem and increase offenses. Signals can be protected through Encryption and prevent from acquiring captured by Scanners.

    There are many statute law demands for implementing the PTMR. The statute law is straight non named the PTMR instead named BWA ( Broadband Wireless Access ) which when obtained can be used to register frequence and so the seller equipment licence. There are regulations and regualtions to be followed for enrollment. The regulations are as follows:

    1. The Licensee shall set up, run and keep the BWA Services every bit provided in the License.
    2. In order to guarantee proper competition among the BWA Services licensees, entire 3 ( three ) licences will be issued to supply countrywide BWA Services in 2.3 GHz and 2.5 GHz spectrum sets. An extra BWA licence ( 4th licence ) may be issued to Bangladesh Telecommunications Company Limited ( BTCL ) in the same footings and conditions including the License Acquisition Fee ( to be fixed by manner of auction ) as shall be applicable to the other BWA licensees.
    3. Two licences will be awarded to the prospective Applicant ( s ) to supply countrywide BWA Services in 2.3 GHz and one licence will be awarded in 2.5 GHz spectrum sets.
    4. The continuance of the Licenses, shall ab initio be for a term of 15 ( 15 ) old ages. Upon termination of the initial term, the License may be renewed for subsequent footings, each of 5 old ages in continuance, capable to the blessing from the Commission and to such conditions, including the payment of any fees, as may be specified herein and/or by the Commission under the Act.

    The operators, within 1 twelvemonth of issue of licence, shall hold to put in minimal 5 full fledged Base Station Transceiver ( BTS ) wireless sites in countries covering each Divisional Headquarters and 3 BTS covering each District.

    Frequency Scope: 2.3 Ghz – 2.5Ghz.

    Frequency Limitaion: 25 Km radius.

    Signing: 5-Tone Advanced Signalling.

    Channel Spacing: 12.5 Khz.

    Intervention: Co-channel Interference, Adjacent Channel Interference and Intermodulation ( Operating frequence scope explained, 2008 ) .

    Recommendation for Telephone Systems to be purchased:

    Now, what is left for the constabulary section is a Telecommunication system. The best possible solution is the PBX ( Private Branch Exchange ) . Housing personal machines and equipments to implement a PBX is a large fuss. Therefore, it is popular and advisable that Hosted PBX be implemented. As the name suggests, a supplier of PBX will make all the necessary work to implement the PBX and most of the equipments will be in their premises which decreases the cost and job of keeping the equipments. And as of privateness and security, the suppliers can be signed with for a QoS ( Quality of Service ) which will include regulations and ordinances of security and privateness of the client ‘s communications through PBX.

    A Hosted PBX includes the undermentioned costs and charges:

    The hardware and apparatus cost included = 1,30,000 BDT/Month.

    If something goes incorrect with the telephone sets or wiring in the user premesis so the users has to face the costs. Their monthly cost on PBX requires as follows:

    Replacing amendss sets= 2,850 BDT/Telephone set.

    Wiring Replacement= 25 BDT/Feet of wire.

    Any harm occuring at the supplier premesis is maintained by the suppliers themselves.

    Premises:

    • BRTC provides licence of PTMR through BWA licences.
    • Investigation beginning has concealed right information.
    • ISP will carry through the demands at the claimed monetary value.
    • PTMR is largely used in Bangladesh for Two-way communicating.
    • Equipments that are required for PBX are approximately the same as denoted above.
    • The characteristics investifation beginning claimed they have for PBX are true and accurate.
    • Hosted PBX in Bangladesh is at the monetary value claimed above.
    • PTMR can be implemented in Bangladesh as claimed above.
    • Legal Requirements obtained from the BTRC web site are accurate.

    Bibliography:

    Network Topologies. ( n.d. ) . Retrieved January Wednesday, 2010, from About.Com: hypertext transfer protocol: //compnetworking.about.com/od/networkdesign/a/topologies.htm.

    Licensing Guidelines. ( n.d. ) . Retrieved January Wednesday, 2010, from BTRC: hypertext transfer protocol: //www.btrc.gov.bd/licensing/guidelines/bwa_guidelines.pdf.

    PMR – Private Mobile Radio FAQ ‘s. ( n.d. ) . Retrieved January Wednesday, 2010, from Icom: hypertext transfer protocol: //www.icomuk.co.uk/categoryRender.asp? categoryID=3796 & A ; page3796=0.

    Professional Mobile Radio. ( n.d. ) . Retrieved Januray Wednesday, 2010, from WikiPedia: hypertext transfer protocol: //en.wikipedia.org/wiki/Professional_Mobile_Radio.

    Repeater applications explained! ( n.d. ) . Retrieved January Wednesday, 2010, from Icom: hypertext transfer protocol: //www.icomuk.co.uk/categoryRender.asp? categoryID=3796 & A ; cCID=15947.

    Operating frequence scope explained. ( 2008 ) . Retrieved January Wednesday, 2010, from iCom: hypertext transfer protocol: //www.icomuk.co.uk/categoryRender.asp? categoryID=3796 & A ; cCID=15944.