INTRODUCTION to network architecture &topologies
In the present time where technology is playing a major role in every sector it is important to communicate and transfer data and information among various locations within seconds. Computer Networking is an architecture which works on exchange of data and information between computers. In respect to transfer of data a physical connection is demanded by means of cables, wireless modems among computers and most commonly used platform of computer network is internet. Data is transformed, directed and terminated through various network nodes of computer devices. These nodes commonly are device like server, hubs, repeaters and routers. When two or more systems share and exchange information they are said to be inter-connected. There are various rules for transfer of data among systems known and network protocols which define data formats and rules in which information can be exchanged. The most widely used protocol is TCP/IP (Chiang, 2008).
TASK 1: UNDERSTANDING OF LAN TECHNOLOGIES
LAN or local area network could be stated as kind of computer network in which computers are inter-connected in a way by which information could be exchange, inter-communication and resource sharing can be implemented. In simple terms it is a network which allows multiple users to access the same resources of a system, regardless of physical location of user or computer resources. The primary usage of LAN architecture is implemented in small area like school, office or college. In LAN computer network architecture, each user can receive and send data addressed to it (Trulove, 2005).Various types of LAN topologies are available and are shared below:
In this type of topology, every computer or system is straightly connected to a custom centralized node. The central station also known as Star Coupler carries two point-to-point links, in which one does work for transmission and one is used for receiving. The basic features of star network include, Firstly it is quite expensive to be implemented. Secondly the speed is quite fast as every node has its particular cable. Thirdly if a cable gets busted then only a single computer gets affected. The whole architecture is completely dependent on central device. It the most general network topology (Local area network(LAN), 2013).
In this type of LAN topology, we design a long centralized cable which looks like a bus is utilized to inter-connect the entire computer or the nodes altogether. Every computer carries a short cable which is inter-joined to the central cable or we can say links to the bus. The salient features of LAN are: Firstly its implementation is very cheap since lesser amount of cables is required. Secondly it is fairly slow as all computers utilize the same cable for transfer and reception of information and data. There can be interruption if the central cable gets damaged (Chiang, 2008).
In this format of LAN topology, the network compromises of various groups of repeaters which are inter-joined by point-to-point links in a confined circle or loop. The links are unidirectional; which means data is transferred in single direction only and all are aligned in similar way. Therefore data is dispersed through the ring in single direction which can be clockwise or anti-clock wise. The ring network can also cope up if the cable is damaged since all computers will be still inter-connected (Oppenheimer and Bardwell, 2002).
The Tree topology is a generalized concept of bus or star topology. It is usually based on hierarchical architecture of nodes. The topmost level of any tree network compromises of a single, 'parent' node, this node connects either a single (or, more commonly, multiple) nodes in the level below through point-to-point links. These lower level nodes are also connected to a single or multiple nodes in the next level down (Edwards and Bramante, 2009).
Now taking in view the best topology which can be suitable for North Manchester Community College (NMCC) which is presently under construction and wants to implement IT infrastructure in its building so that students present in the different departments can easily access internet and always remain connected with each other, the topology which we will consider will be RING topology because of its architecture and advantages above other topologies (Dooley, 2009). The reasons for choosing RING topology are listed below:
- This kind of network topology is very systematic. Every node is able to transfer data when it receives an empty token. This results in very less chance of collision. Moreover the traffic flow is unidirectional at a very fast speed.
- Secondly in circumstances where load of transfer and reception is much on network its performance is reliable.
- The central server or main network node need not manager internal transfer among nodes or computers. Moreover any appended constituents do not alter the performance of the network (Dooley, 2009).
- Finally every node or computer has balanced share of resources. There is an ease of identifying any critical issue if any problem occurs.
Now taking in mind the concept of latency and bandwidth and comparing them for the network of the college we find that, Latency is stated as time required in initiating the process of communication. On the contrary Bandwidth refers to how fast information can be accessed. A common example on latency and bandwidth is a call generated to customer care of your mobile phone service provider, firstly we need to identify the number then we need to dial it and then we need to wait in queue until the call is given response. Bandwidth relates to second part where one needs to discuss the problem with the accurate person. Similar is the process of communication and data transfer where two factors are major: First is the time to initial i.e. the latency and adding up the amount of data or information which one needs to transfer multiplied by the speed the amount of information you need to transfer multiplied by the speed at which it can be transmitted (the bandwidth) (Singh, 2002).
TASK 2: DEMONSTRATE YOUR DESIGN OF A LAN NETWORK
In respect to design a three layer hierarchical model for the LAN infrastructure of North Manchester Academy we need to go through the concept of three layers hierarchical model and then implement it. A hierarchical network model accommodates a framework with help of which network designers are able to assure that flexibility is achieved and network is easy to implement and troubleshoot.
Hierarchical Network Design Layers:
As shown in figure given below the hierarchical network model constitutes of three layers: Firstly the Access Layer which is associated with local or remote user access to network. Secondly comes the distribution layer which provides connectivity which is based on policies, and finally there is the main core layer which serves as a backbone by granting faster transfer to satisfy connectivity and transfer needs of the distribution layer (Long and Irwin, 2004).
Each hierarchical layer carries specific functionality, which allows the network designer to opt for the accurate systems and specifications depending on their functions within the model. In this manner more accuracy and capacity planning with reduction in costs of implementation can be gained.
By the access layer interface is gained with end devices as like systems, printers to issue access with the remaining network. An Access layer compromises of routers, switches, hubs, bridges and wireless access points. The major task of this layer is to direct a way of connecting devices with the network and supervising the devices which are granted access to communicate on network (Dooley, 2009).
With the help of distribution layer network designer can combine the data receipted from the switches of access layer till it is transferred to the core layer for directing it to the end destination. Network flow is controlled by distribution layer by applying policies and details broadcast field operating routing functions among virtual LAN (VLAN) described at the access layer. VLAN authorizes to segregate traffic on a switch into different sub-networks. As for instance in a college campus it may separate traffic according to faculty, students, and guests.
Distribution layer switches are usually high-performance devices that have high availability and redundancy to assure reliability.
The core layer of the hierarchical design is the main backbone of the inter-network.
The core layer is vital for interconnection among devices of distribution layer; therefore it is necessary for core to easily available and repetitious. The core layer may also inter-connect with the internet information. It must have capability of expediting data quickly since it aggregates the traffic from devices of distribution layer (Dooley, 2009).
The North Manchester Community College (NMCC) is currently under construction and the IT Infrastructure needs to be planned and implemented before the college opens. NMCC will be a dedicated media college; the students will have access to a dedicated building away from the main block in which state of the art machines will be placed. So as per the college requirement, a network infrastructure is a group of computer systems which all are interconnected to the each other and linked by the different parts of telecommunication architecture. In the college the network infrastructure gives the different parts and configurations like- routers, cables, backbones, wireless network access point, switches, protocols, and network methodologies. The network infrastructure includes one or more computer systems which are connected to the internet connection and through the hub to systems link the computers to the network and the all systems are connected to each other.
There are various network requirements which have emphasis on the entire network as discussed below: Firstly introducing new network applications or altering the existing one like database or DNS (Domain Name Server). Designer can enhance the efficiency of network addressing or directing changes in protocol and incorporating new security standards.
Evaluate different LAN components to improve the networks sustainability
There are various components of LAN which are required to improve network sustainability and are discussed below:
- Network Adapter: A system requires a network adapter to inter-connect with the network. The basic function of network adapter is to convert computer data to electronic signals. The network access element of its task is called MAC (Media Access Control). Every computer is assigned a physical address termed as MAC address. The serial number equipped on network adapter is MAC address. The wireless equivalent is referred as a Wireless Network Interface Controller.
- Network Medium: Every network needs medium of cables for data transfer. The most commonly utilized cable in networks is UTP (Unshielded Twisted Pair). It is also termed as Ethernet Cable. Ethernet is the most widely implemented set of standards for the physical properties of networks. Wireless networks do not require cables; they send data on radio waves generated by the WNIC (Helal, 2002)
- Cable Connectors: In cable wire networking most commonly used connector is RJ45. Every system is equipped with networking capabilities similar to RJ 45. It is also known as Ethernet Port. The plug of RJ 45 is quite similar to a telephone plug and is used to connect UTP or STP cable.
- Power Supply: Every network requires power supply. A wireless network access the current to generate radio waves, On the other hand cabled network sends data interpreted as an electronic pulse.
- Hub/Switch/Router: In a wired networking system one computer cannot connect to other without any external medium. A hub is used to repeat any signals coming to any of its ports. A cable leads from each port to one computer. Switch is used to send signal on to the computer with the address written in the arriving message. Whereas a Router is capable of forwarding messages throughout the world. Larger networks sometimes use routers for their LAN traffic. The wireless networking device is called a "wireless router." (Long and Irwin, 2004).
- Network Software: Software which is used for communication among computer is termed as Network Software. The NOS (network operating system) is the control program that resides in a server or workstation within an LAN. This controls the network.
TASK 3: BE ABLE TO IMPLEMENT AND MANAGE A LAN NETWORK
Produce a packet tracer file which shows a working LAN, this should be fully working with a minimum capacity for 30 networked devices
A packet tracer is a Cisco Router simulator which is used in training, research and education of network simulation. This tool is developed by Cisco and freely accessible. Features of Packet Tracer includes: It supports an array of simulated Application Layer Protocols. It provides a realistic functionality of simulated network.
Steps to be followed include:-
- Select Number of systems and switches and push them towards editor.
- Select a copper cable and join them.
- Assign various ip-addresses to them apart from switches.
- Select a message and send it to any system from another system (Trulove, 2005).
Implement port security on the LAN switches
The main feature in the networking is that how to make secure our organization internal network. The port security feature remembers the Ethernet MAC address connected to the switch port and provides only the MAC address to transfers on that port. In the network administrators configured the switch to transfers and then the SNMP finds to their network monitoring solution that the ports disabled for security reasons. When we using the port security then we have to aware about the devices and avoid devices from accessing the network that is increases the security (Edwards and Bramante, 2009).
Provide evidence of monitoring and troubleshooting
The monitoring and troubleshooting in the networking it is also a technique. The computer goes blank before saved the data so that the browser window freezes for no reason. That’s known as the troubleshooting. In the networking the user always used the security software and monitors the attacks from the other user (Oppenheimer and Bardwell, 2002).
LAN Network Topology –
Network topology is a very important term to understand the key elements to troubleshooting and helps in what now we can decide what action will perform on the facing problem. For implementation of technology we have considered the Ring Topology. I chose the ring topology because this topology mainly found in the Organizations and home networks. It is very popular topology. And as per the report requirement we need the college network so that we have chosen the ring topology (Knopp, 2006).
Evaluate the performance of the LAN and document your results
For evaluate the performance of the LAN then we have to consider main three points in the networking.
- Adjusting LANs for optimum communications performance
- Adjusting LAN lines for optimum communications performance
- LAN line speed considerations for IOPs (Input/ output processors)
Through these points we can evaluate the performance of the LAN (Trulove, 2005).
We have elaborated the concept of network architecture and topologies and a framework for designing the three layer architecture for the North Manchester Academy has been implemented and also explanation of the working of LAN, security terms, performance, port switches and maintenance and communication through the LAN networking has been explained in this report.
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