History Of The Bus Topology

History Of The Bus TopologyA bus topographic anatomy is a electronic network set up in which invitees be affiliated to a segment of phone line in the logical shape of a line, with a terminator at each end. A bus topology connects each figurer or nodes to a oneness segment trunk. All nodes on the network sh atomic number 18 a common bus and role a multi-drop transmission medium. Bus network each(prenominal)ows only one device to transmit at a time. A distri excepted access protocol determines which station is to transmit. The signal goes from one end of the bus to a nonher. A terminator is needed at each to cut round the signal so it does not reflect back across the bus. CSMA/CA, media access method, is utilise to control the collisions that take place when two signals placed on the outfit at the same time.There be two lineaments of bus topology Linear Bus Topology and Distributed Bus Topology. In Linear Bus Topology, totally nodes of the network are connected to a comm on transmission medium which has exactly two endpoints. Distributed Bus in which all of the nodes of the network are connected to a common transmission medium which has more than two endpoints that are created by adding branches to the main section of the transmission medium.Bus networks do best with a limited number of devices. If more than limited estimators are added to a bus, performance lines will be result. If the backbone cable fails, the encompassing network effectively becomes unusable. image Bus TopologyRing TopologyRing network topology has no central server and connects computers in a circle of point-to-point fraternitys. Each node handles its throw applications. And also shares resources over the entire network. If one node becomes break down, the others are still able to maintain contact with one another. Such a network is best for decentralized systems because no priorities are required.The signal is transferred through a attribute for one station to the next. When a station needs to transmit, it grabs the token, attaches info and an address to it. And then routes it around the ring. The token travels a immense the ring till reaches the destination address. The receiving computer replies an acknowledgment to the sender source. The sender then releases the token for use by another computer. Each station on the ring has equal access but only one station stub use token at a time. To countenance an orderly access to the ring, a single electronic token passes from one computer to the next around the ring. A computer can only transmit entropy when it captures the tokenFig Ring TopologyStar TopologyA star topology is one of the virtually use common network topology where each of the devices and computers on a network connect to a central hub or sometimes bonny a switch. On a star network, data passes though the hub to its destination. The hub manages and controls all functions of the network. It also performs as a repeater for the data fl ow. In a star network, the entire network is dependent on the hub so if there is a problem with the hub, the entire network is not working. This makes it easy to troubleshoot by offering a single point for error connection and at the same time the dependency is also very high on that single point. Every computer in the network is safe when the hub is safe. This type of network also offers more privacy than any other network.The star network topology requires more cable than the wonted(prenominal) Bus topology. A common cable that is utilise in star network is the UTP or the unshielded wrestle pair cable. Another common cable that is use in star networks is the RJ45 or the Ethernet cables.If one computer fails in the network, it does not affect any other computer in the network and the purposes of this computer can be easily changed to the next computer easily use the controls of hub. In a Star Network Topology it is executable to prevail all the important data backups on the h ub in a private f onetime(a) so if one computer fails, it can still use data using the next computer in the network and accessing the backup cross-files on the hub.New devices or nodes can easily be added to the Star Network by just extending a cable from the hub. Because of the hub controls everything, the addition or removal of devices are done using the hub. If the hub adds a device such as a printer or a fax machine, all the other computers on the network can access that radical device by accessing the hub. The device is no need to be installed on all the computers in the entire network. The central function is cost effective and easier to maintain.Fig Star Topology function TopologyA type of network configuration where each of the computers and network devices are interconnected with one another allows for virtually transmissions to be distributed even if one of the connections goes down. This type of topology is not commonly used for most computer networks because it is dif ficult and expensive to bemuse redundant connection to every computer.In Mesh network, it can route data, vocalization and instructions between nodes. It allows for continuous connections and reconfiguration around broken or blocked paths by 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. The network can still operate even when a node fails or a connection goes bad.On a mesh network, messages can send via any of several(prenominal) possible paths from source to destination. It employs one of two connection arrangements, full mesh topology or incomplete mesh topology. In the full mesh topology, each node is connected directly to each of the others. In the partial mesh topology, some nodes are connected to all the others, but some of the nodes are connected only to those other nodes with which they exchange the most data.Fig Mesh TopologyDifferent types of cablesDifferent types of n etwork cables are used depending on the kind of network. The type of cable used for a network depends on the networks topology, protocol, and size. If a network has larger number of network devices, it will need cables that provide high speed and error free connectivity.Some of the cables being used directly are Unshielded Twisted Pair (UTP) cables, coaxial cables and fiber optic cables. The UTP cable is the most popular variety, largely used for school networks as it transfers data at atomic number 6 mbps. Coaxial cables hold a single hog conductor at their fondness. A plastic layer provides insulation between the concentrate on conductor and the braided metal shield. The outer metal shield blocks out outer interferences such as lights, motors and other computers. Fiber optic cables consist of a center glass core surrounded by several layers of protective materials. It transmits light rather than electronic signals and transfers signals over much longer durations than coaxi al and twisted pair cables.Network cables are the backbone of any network. However, today several networks are switching over to other mediums of data transfer such as high frequency receiving set signals, and infrared light beams to connect the workstations. These systems are not only fast and effective, but also do a substance with the problem of maintain several hundred feet of cables spreading across the workspace. With such technologies coming to the forefront, the future may well tilt in favor of wireless systems.10Mbps Networking monetary standardCable emblemSegment LengthConnector10 instauration2Thin Coaxial185 metersBNC10BaseTCategory 3, 4, 5 twisted pair100 metersRJ-4510BaseFLFiber-optic2000 metersSC/STb) Advantages and Disadvantages of medium.Media TypeMaximum Segment LengthSpeedCostAdvantagesDisadvantagesUTP100 m10 Mbps to 1000 MbpsLeast expensiveEasy to install widely acquirable and widely usedSusceptible to interference can cover only a limited distanceSTP100 m10 M bps to 100 MbpsMore expensive than UTPReduced crosstalk more resistant to EMI than Thinnet or UTPDifficult to work with can cover only a limited distanceCoaxial500 m (Thicknet)185 m (Thinnet)10 Mbps to 100 MbpsRelatively inexpensive, but more costly than UTPLess susceptible to EMI interference than other types of copper mediaDifficult to work with (Thicknet) limited bandwidth limited application (Thinnet) damage to cable can bring down entire networkFiber-Optic10 km and farther (single-mode)2 km and farther (multimode)100 Mbps to 100 Gbps (single mode)100 Mbps to 9.92 Gbps (multimode)ExpensiveCannot be tapped, so security is better can be used over great distances is not susceptible to EMI has a higher data rate than coaxial and twisted-pair cableDifficult to terminatec) Recommendation.Star topology would be the best way to use for renewing Townsville Police surgical incision Network infrastructure because of in-house network (LAN) structure. Star topology should be also used for p ursual reasons.Easy to install and reconfigure.No disruptions to the network when connecting or removing devices.Easy to detect faults and to remove parts.Less expensive.Includes robustness, that is, if one link fails, only that link is affected, other links remain active.It has been said that Townsville Police section covers an country of 100 square kilometers and Townsville is divided into four districts (Northern, Eastern, Western and Southern). For that reason, the switch should be placed in the center of four districts. So, the network cable must cover 50 kilometer and the switch must be gigabit Ethernet. Therefore, UTP with cat6E is the most adapted network for such an area of network.Category 6 UTPCategory 6 resists gigabit Ethernet and is recognized by standards bodies as reenforcementing 10GBASE-T, however there are demarcations that must be considered. The IEEE 802.3an standard cites a 55 meter distance limitation for standard category 6, which is not universally ag reed upon within the TIA and ISO standards.TIA TSB 155 recently released a skilful expediency Bulletin covering additional parameters for running 10GBASE-T on standard category 6. In this document a 37 meter distance limitation is cite for 10GBASE-T on standards compliant category 6 systems. Between 37 meters and the IEEE referenced 55 meters, standard category 6 may support 10GBASE-T, but it is possible that the installer may crap to use alien crosstalk mitigation techniques such as unbundling cables or replacing patch cords to improve the galvanising parameters to allow 10GBASE-T to work properly. Above 55 meters, it is unlikely that category 6 UTP would work properly without a large amount of mitigation to reduce alien crosstalk. A key takeaway is that using category 6 UTP for 10GBASE-T should be focused on existing installations, not new installations. The choice for new installations knowing to support 10GBASE-T should be increase category 6 UTP, STP or optical fiber sy stems.Category 6 Advantages Cost and size of media, relative to augmented category 6 and STP Installed base currently the dominant UTP cabling standard Installation widely acceptedCategory 6 Disadvantages Limited distance for 10GBASE-T away noise suppression at 100 m, relative to shielded systems or augmented category 6 designate 2a)Nowadays, there are several usages of Internet by means of so numerous ways. There are terce basic Internet functionInformation (browsing, online-shopping, etc.)Communications (mail, chat, Video conferencing, etc.)Files sharing (downloading, uploading, etc.)b)The connecting suitable for above severs are as followsFor Information serviceIt can cover only 100 Kbits/s ordinarily prove adequate.For CommunicationFor photograph conferencing, bandwidths of no more than 384 Kbits/s usually prove adequate. As for chatting conversation, especially for yahoo chat, 28 Kbits/s should be enough.For File SharingAs for file sharing, bandwidths of more than 1 Mbit/s are most suitable.c) The Internet Service Provider in MyanmarMyanmar Posts and TelecommunicationsThe Myanmar Posts and Telecommunications (MPT), is the sole provider of telecommunication work in Myanmar. It is a Government Agency, direct low the Ministry of Communications, Posts and Telegraphs. It was founded in 1884 as a small Department of Posts and Telegraphs and has grown into the present day Myanma Posts and Telecommunications with approximately 13800 employees of which about 380 are managerial level staff. The present organization is headed by the Managing Director and a General Manager as his deputy. There are nine major departments operating under respective deputy general managers/chief engineers in the fields of administration, works and inspection, planning, training, finance, stores, automatic telephones, overseas communications and long distance communications. The three main categories of services rendered by MPT are the postal services, telegraph services an d telephone services, for both domestic and international communications.d)Since, there is only one ISP in our country (Myanmar) we have to use MPT (Myanmar Posts and Telecommunication) as an ISP for our country.Task 3a)Methods of Two-Way Voice communications bipartisan voice communications (radios) are essentially available in three typesHand-held portable,Vehicle-mounted mobile, andDesktop-base stationThere are also unique nonpartizan radio devices such as indoor and outdoor call nichees and one-way radio receivers for wireless paging.Hand-held portable two-way radios are the walkie talkie type of radios. As ruled by the FCC (Federal Communications Commission), hand-held radios may not have more than 5 watts of power.Vehicle-mounted mobile two-way radios mount in a car or truck and they use the vehicles battery for power. They may have their own antenna, but better range is achieved by using an externally-mounted antenna.Desktop base station radios use wall AC power and they too may have a built-in antenna, but this antenna may be disconnected and then connected to cable that leads to an external-mounted antenna. The higher the antenna is mounted, the better the range.The vehicle-mounted mobile radios are usually used as base stations by just adding an AC to DC power converter.Mobile and Base station radios are usually more powerful than hand-held radios and may have as much as 100 watts of power.FrequenciesThere are two major frequency formats for two-way radios. They are Ultra High Frequency (ultrahigh frequency) radio and Very High Frequency (VHF) radio. Neither frequency band is inherently better than the other. They each have their pluses and minuses. Both formats are effective ways to communicate with another person.UHF radioThe UHF radio band for commercial radios is between 400 512 MHz. Until recently, it wasnt widely used. Now, the UHF radio frequency is used for two-way radios, GPS, Blue-tooth, cordless phones, and WiFi.VHF radioThe VHF radio ba nd for commercial radios is between 130 174 MHz. FM radio, two-way radios, and television broadcasts operate in this range.Both UHF and VHF radios are prone to line of sight factors, but VHF a smaller more so. The waves make it through trees and rugged landscapes, but not as well as UHF frequencies do. However, if a VHF wave and a UHF wave were transmitted over an area without barriers, the VHF wave would travel almost twice as far. This makes VHF easier to broadcast over a long range.Two-way radios, hand-held portable, vehicle-mounted mobile and desktop base station are full duplex.b)Legal requirement for operation systemTwo -way radio devicesTwo-way radio powerAntennasChannel usagesFCC LicensingAudio AccessoriesCases, Holsters, and Belt ClipsBatteriesRepeatersDrop-in ChargerMulti-charging UnitsSelectable PowerOperatorsAdministratorsControl stationAdditional and optional knowledge of two-way voice communication technologyOverall knowledge of how to use a selected two-way voice co mmunication device be of setting up and operating the system in my countryAs for hand-held two way voice communication device, according to amazon.com, the costs are as followsFor Cobra CTX400 GMRS/FRS 2-Way Rechargeable Radio with Hands-Free function (Pair)$36.88For Townsville Police Department, total cost for using hand-held two way voice communication device is up to $2065.28.d) Limitations of each method (interference, range, etc.).Product Features22 Mile Range, 22 Channels 121 Privacy Codes10 Channel NOAA radio Hands-free operation (VOX)8 Rechargeable AAA batteries, and a 2 port desk battery charger includedMaximum range extender and belt clip included for maximum efficiency and carrying easeLead-Free, Eco-Friendly Packaginge) As for sideline feature Highlights, tow way voice communication should be set up.VOXThe Voice Activated Transmit (VOX) feature enables us to use our radio hands free. When VOX is turned on, the radio will automatically begin transmitting when we spe ak, without pressing the push-to-talk button. VOX works well for any application.On most VOX-capable radios there is a cold-shoulder delay between when we start speaking and when the microphone turns on so the first part of the conversation may be clipped. Most radio users vote down this by repeating the first word.Military Specification StandardsIn an effort to achieve standardization objectives for purchases of products used by the military and other government organizations, the U.S. Department of Defense created standards that these products must meet. We will see these standards called military standard, MIL-STD, or MIL-SPEC. These standards ensure products meet certain requirements, commonality, reliability, compatibility, and identical defense-related objectives.According to Military Specification Standards, Townsville Police Department should be used Cobra CTX400 GMRS/FRS 2-Way Rechargeable Radio.Task 4a)Since AVAYA IP Office 4.0 is only software for PBX telephone system, the main equipment that would be installed is only software. The process for the installation is as followsInstallationTo establish and maintain an IP DECT installation, a network infrastructure is assumed, which comprises at least the following componentsIP Base postIP DECT phoneIP OfficeTFTP server (which can be the IP Office or 3rd Party)Depending on the operational requirements the following services should be providedDHCPSNTPDNSWML/HTTPSyslog daemonb) AVAYA IP Office 4.0 Telephone formation (IP DECT)Digital Enhanced Cordless TelecommunicationThe standard (ETS 300 175) essentially specifies the air interface, cognise as the radio interface. Voice and data can both be transmitted via this interface.DECT key technical characteristics areFrequency range approximately 1,880 1,900 gigacycle (approximately 20 MHz bandwidth)10 carrier frequencies (1,728 MHz spacing) with 12 time slots eachDoubling the number of time slots (to 24) using the TDMA processNet data rate per channel of 32 kbit/s (for voice transmission using ADPCM)Voice coding using the ADPCM methodMaximum transmission power of 10 mWGAP GenericAbout the IP DECT Base sendThere are two types of IP Base Station. All IP Base Stations have the same hardware and software capabilities.Indoor IP Base StationThe indoor IP Base Station is for indoor use only. It can be powered by a mains adapter or by 802.3af compliant power over Ethernet. placardFor Australia and New Zealand the mains adaptor is not currently supported. Only 802.3af compliant power over Ethernet is supported.Outdoor IP Base StationThe outdoor IP Base Station can be used outdoors or indoors. The outdoor IP Base Station can only be powered by 802.3af compliant power over Ethernet.NoteAvaya Power over Ethernet adaptors are non 802.3af compliant, and therefore cannot power the ADMM.One of the IP Base Station within an IP DECT installation must be elect (at installation time) to operate as the ADMM. This ADMM mode is in addition to the normal IP Base Station functionality that all the other base stations retain.c) Costs for installing AVAYA IP officeThere are two models of phones the 3701 and 3711 phones. Avaya Kirk DECT phones (WT9620 and DT20) function on the IP DECT solution, but the functionality is limited.AVAYA Partner 18D- Digital phone3 new from $95.00Avaya 6408D+- Digital phone -multi-line operationAvaya 5621SWP IP Phone (700385982)Avaya IP400 Analog Trunk 4 cardAvailable at external website Atlas Phones for $199.00d) Costs for operating the systemAvaya IP Office Smart Card w/Voicemail Pro like new, available at external website Atlas Phones for $1,095.00.Premise-based IP PBX systems vary exceedingly widely in cost and even more so as we look at wide-scale deployments and future growth and additions to a system. A basic premise-based box for a relatively small number of users say up to 20 in a single location can cost less than $1,000 excluding the phones themselves. scarcely expansion costs and other branc h locations can change the cost equation dramatically. In addition, we will have on qualifying costs related to connection to the regular phone system and whatever connection costs are imposed by our backbone supplier. These ongoing costs are nevertheless going to be considerably lower than any other form of phone system. They should be lower than hosted VoIP solutions, and they will be dramatically lower than any older PBX and telecommunications provider.Phones are an additional cost, but when buying a premise-based IP PBX system, we often have greater flexibility than in any other arrangement. We can take up to go with very low-cost, no-name or bottom-of-the-line phones (which are still perfectly capable) all the way up to top-notch phones from manufacturers such as Polycom and Siemens that provide usability benefits (although often at a price premium).For Townsville Police Department, AVAYA Partner 18D- Digital phone should be used up to 6 base stations as for stages, one Headq uarter reaction Area, four Districts, and one serious crime squad.e) Recommendation for AVAYAThe IP DECT solution delivers all the benefits of IP-based converged communications with the convenience of in-building wireless communications. Designed to support a large number of users, the IP DECT system enables users to carry a wireless phone and get full access to all the features they are addicted to using at their desk phone. The IP DECT solution, which connects to the IP Office using a variant of the H.323 protocol, can support users in different offices that are connected via a WAN. An IP DECT cordless handset can travel from one office to another, making and taking calls.The DECT over IP system comprises the following componentsAt least one IP Base Station connected over an IP network and offering IP DECT as a wireless interface.A maximum of 32 IP Base Stations are supported.IP Office Small Office Edition, IP Office 406v2, 403, 406v1 or 412 with available VCM resources.IP DECT p hone Avaya 3701 and Avaya 3711 wireless phones.A maximum of 120 IP DECT phones are supported.Avaya IP DECT Mobility Manager (ADMM) management interface for IP DECT WirelessSolution, which runs on either one of the IP DECT Base Stations.The picture displayed next page gives a graphical overview of the architecture of the IP DECT Wireless solution. The IP Office, ADMM and the IP Base Stations communicate through the IP infrastructure. The IP Base Stations and the IP DECT phones communicate over air.Graphical overview of the architecture of the IP DECT Wireless solutionTask 5Task (5)This is the detail report for the overall tasks sorting from Task 1 to Task 4.In Task 1, the Townsville Police Department should be used Category 6 UTP by the following reasons Cost and size of media, relative to augmented category 6 and STP Installed base currently the dominant UTP cabling standard Installation widely acceptedAnd it is suitable for Townsville Police Department.Category 6 supports gigabit Ethernet and is recognized by standards bodies as supporting 10GBASE-T, however there are limitations that must be considered. The IEEE 802.3an standard cites a 55 meter distance limitation for standard category 6, which is not universally agreed upon within the TIA and ISO standards.TIA TSB 155 recently released a Technical Service Bulletin covering additional parameters for running 10GBASE-T on standard category 6. In this document a 37 meter distance limitation is referenced for 10GBASE-T on standards compliant category 6 systems. Between 37 meters and the IEEE referenced 55 meters, standard category 6 may support 10GBASE-T, but it is possible that the installer may have to use alien crosstalk mitigation techniques such as unbundling cables or replacing patch cords to improve the electrical parameters to allow 10GBASE-T to work properly. Above 55 meters, it is unlikely that category 6 UTP would work properly without a large amount of mitigation to reduce alien crosstalk. A key t akeaway is that using category 6 UTP for 10GBASE-T should be focused on existing installations, not new installations. The choice for new installations designed to support 10GBASE-T should be augmented category 6 UTP, STP or optical fiber systems.Townsville Police Department has been restructured within an area of 100 square kilometers. precisely Townsville PD could not over more than 500 square kilometers because the head departments are divided into four districts (Northern, Eastern, Western and southern). Cat 6 UTP could support that area.For Task 2, the services for internet connections are as followsInformation (browsing, online-shopping, etc.)Communications (mail, chat, Video conferencing, etc.)Files sharing (downloading, uploading, etc.)These services are the most common used for internet.And recommended connection speeds are as followsFor Information serviceIt can cover only 100 Kbits/s usually prove adequate.For CommunicationFor video conferencing, bandwidths of no more th an 384 Kbits/s usually prove adequate. As for chatting communication, especially for most chatting communications, 28 Kbits/s should be enough.For File SharingAs for file sharing, bandwidths of more than 1 Mbit/s are most suitable.There is only one Internet Service Provider in our country, Myanmar Ports and Communications.In Task 3, there are too many options for two -way voice communication devices. Two-way voice communications (radios) are essentially available in three typesHand-held portable,Vehicle-mounted mobile, andDesktop-base stationThese are most common used for two-way voice communication. And I provided the recommendation the device as followsMilitary Specification StandardsIn an effort to achieve standardization objectives for purchases of products used by the military and other government organizations, the U.S. Department of Defense created standards that these products must meet. We will see these standards called military standard, MIL-STD, or MIL-SPEC. These standa rds ensure products meet certain requirements, commonality, reliability, compatibility, and similar defense-related objectives.According to Military Specification Standards, Townsville Police Department should be used two way voice communication technology.For Task 4, the main equipments that would be installed are just only the software. There are so many options and vendors that provide telephone known as PBX. Among those vendors, I chose AVAYA IP Office 4.0 Telephone System (IP DECT). As for Townsville Police Department, like military office, it is important to choose the right products. The IP DECT solution delivers all the benefits of IP-based converged communications with the convenience of in-building wireless communications. Designed to support a large number of users, the IP DECT system enables users to carry a wireless phone and get full access to all the features they are accustomed to using at their desk phone. The IP DECT solution, which connects to the IP Office using a variant of the H.323 protocol, can support users in different offices that are connected via a WAN. An IP DECT cordless handset can travel from one office to another, making and taking calls.