LAN Reliability and Availability - Research Paper Example

? LAN Availability and Reliability LAN Availability and Reliability Introduction The world has reached the point that nothing could be done without network interconnection. However, the reliability and availability of network is of high importance in order for companies and organizations to run smoothly. The changing level of technology has a great impact on organizational operations globally, especially in communication, which is essential in any organization. The process through which information is passed from one place to another becomes imperative due to the requirements of time and information integrity. Organizations that have employed the use of Local Area Network, or LAN, can access information and resources of all persons and departments linked to the network. 1 It is important for the networked organizations to understand the various networking terms, conditions and systems operation in order to ensure that the system would not be compromised. In this manner, information would be available and reliable and serve the operational requirements of the organization. Since not all members of the organization would be able to understand the framework of the network, it is necessary to employ network administrators that would ensure the smooth operations and availability of the network. 2 With the network functioning properly, the organization can deliver their products and services to the consumer or end-user without restraint that can result from unpredictable network malfunctions. The network administrator should be the one with the appropriate training so that he/she could understand the network architecture and impacts of specific system failures on the general network. 3 LAN refers to a “communication network, limited in geographic scope”. 4 The network’s hardware components are: a) transmission medium (e.g. twisted pair, fiber optics, coaxial cable), b) mechanism for control of transmission, and c) network interface (for host computers, devices or nodes of network). 5 To meet the requirements of availability and reliability, redundancy approach is usually applied in the system. 6 This approach uses a back up path for every connection so that recovery is possible when failure occurs. 7 Network Availability The ability of the organization to benefit from any network relies on the availability of the specified network. However, for a network to be available most of the time, it must be reliable in order to maximize its use within the infrastructure. Both reliability and availability of a network are interdependent. A network cannot be reliable if the framework is not available to all the units or departments required to connect with it. Thus, both concepts must be handled together since one would affect the other and the organization in general. 8 Network availability refers to the fragment of time wherein the network is in service. 9 Availability of the network may fail if a disaster strikes, and in case of large-scale disaster, many link failures may occur. 10 Computer networks should establish the required infrastructure that would meet the needs of the applications that will be used. 11 Studies have indicated that one measure of the computer network performance is its availability. 12 The availability feature would be particularly important for applications used in banking transactions, e-commerce, and other online transactions. 13 The components of the network that may be prone to failure and affect availability are the a) hosts (e.g. clients, servers in different departments, middle level corporate servers, data tier corporate servers), b) interconnection equipment (including hubs, routers, switches), and c) individual links. 14 The availability concept has become more critical due to complex issues and interconnections distributed across numerous computers. 15 It is also dependent on the accessory devises included to make it functional. 16 Availability has always been an important characteristic of systems but becomes a more critical and complex issue for the network. By their nature, network services are commonly distributed across several computers and can depend on various auxiliary devices as well. 17 There is a primary DNS server that contains the index of all the domain names and addresses of all websites in the Internet system. 18 When the Domain Name System, or DNS, is stored in a single server, a crash would eliminate the capability of the DNS over the network involved. Thus, to avoid this scenario, the DNS must be supported by distributed servers. In this manner, when one server malfunctions, the DNS access will not be hampered. Configuring DNS into several servers would avoid the impact of failures and unavailability of the network. Network outages also occur once in a while. An outage can be avoided by upgrading hardware, software and a server. 19 The file system should also be maintained in a proper manner so that errors in the system memory can be avoided. The system administrator has to perform regular maintenance and restoration of the system. Restoration would include resetting of routers or restoring them to a particular configuration that would enhance information delivery. 20 Outages may also happen intermittently, e.g., during weekends, which would reveal “relatively low availability numbers.” 21 Such weekend outages may not even be noticeable. The networking sector would use the concept “high availability” when referring to the technology and systems which are engineered for availability, reliability, and serviceability. These systems comprise redundant hardware (such as disks or power supplies) and intelligent software (such as load balancing and fail-over functionality). Of course, attainment of high availability would also entail high expenses. Network Reliability Reliability refers to the attribute of any part of the computer system that could perform according to its specifications. Availability relies heavily on network reliability. Network reliability, in a limited sense, refers to the “simple numerical property of an analytic graph model that represents some topological features of a real network”; while in the general sense, it is the measure of effectiveness of the network in “performing required network operations.” 22 Reliability is one of the three important attributes that a computer component should have before acquiring hardware, software, or other applications. Reliability is connected with the topology and method for control of the network, which are the star, bus, and ring topologies. 23 The Institute of Electrical and Electronics Engineers (IEEE) lays down the rules for preventive and operational failures, so that reliability and integrity of the network can be maintained. 24 Proper configuration of the hardware and software resources is another factor in enhancing the reliability of the network system. 25 To ensure reliability, the system administrator could also change some delicate components responsible for relaying information 26 The data handling capacity of the system can also be upgraded so that a large volume of data can be transmitted within a short period of time. 27 The network infrastructural issues should be determined during the planning stage taking into consideration the needs of the organization and the changing systems and technologies. 28 Reliability may be affected by several causes, such as physical destruction which may be intentional (like sabotage), accidental, or environmental (like earthquake or flood). 29 Failure may also result from overloading of the system. Managing of the traffic overload is a way to protect the system; thus, the designer or engineer must anticipate the additional demand for bandwidth. 30 Measures of reliability though focus on intentional causes, such as an attack. There is also a probabilistic measures that focus on random attacks. Failure of the system may occur any time, but what is important is the capability of the network to “recover from a complete loss of a component.” 31 Conclusion An available and reliable network would allow sharing of resources and information, as well as finding the same in the shortest time possible. 32 However, these attributes would be affected by the poor system structure which can result in low accessibility. 33 While the engineer has to implement the plan and design of the infrastructure in order to attain high reliability and availability, the system administrator has the obligation of maintaining reliability and availability through proper auditing and monitoring of the system. 34 Works Cited Availability Concepts for Networks and Systems. 2011. Accessed November 10, 2011. http://compnetworking.about.com/library/weekly/aa092400b.htm. Clark, David D., Kenneth T. Pogran, and David P. Reed. “An Introduction to Local Area Networks”. Proceedings of the IEEE, vol. 66, no. 11, 1978 November, pp. 1497-1517. . Coelho, Flavia S., Jacques P. Sauve, and Claudia B. Abbas. “Availability Evaluation of Networks: An Approach for N-Tier Client Server Architecture”. Revista Facultad De Ingenieria, U.T.A. (Chile), vol. 11, no. 1, 2003, pp. 25-32. Colbourn, Charles J. “Network Reliability: Numbers Or Insight?” Annals of Operations Research, 33, (1991), pp. 87-93. Accessed November 10, 2011. . Levitin, Gregory, ed. Computational Intelligence in Reliability Engineering: New Metaheuristics, Neural and Fuzzy Techniques in Reliability. New York- USA: Springer, 2007. Liew, Soung C., and Kevin W. Lu. “A Framework for Characterizing Disaster-Based Network Survivability”. IEEE Journal on Selected Areas in Communications, vol. 12, no. 1, 1994 January, pp. 52-58. Accessed November 10, 2011. . Mobilkom, Austria. Networks 2004: 11th International Telecommunications Network Strategy and Planning Symposium. Vienna, Austria : Margret Schneider, 2004. Penkler, Dave, Manfred Reitenspiess, and Francis Tam. Service Availability: Third International Service Availability Symposium. Helsinki, Finland: Springer, 2006, May 15-16. Tornatore, Massimo. “Availability Design of Optical Transport Networks”. IEEE Journal on Selected Areas In Communications, vol. 23, no. 8, 2005 August, pp. 1520-1532. Accessed November 10, 2011. . Read More