Review of Telephone and Data Network - Research Paper Example

? Full Paper Current LAN Topology After analyzing the network, workstations are distributed in to segments, as there are several hubs on the network each of one is indicating a gateway to the terminals connected to them. The network architecture of Albany has three different segments. The first network segment includes the workstations of the employees. The second network segment is connected to all the servers, and the third network segment consists of network devices that are connected to the WAN interface. The plastic fan plant that is located in China has total six network segments. There are total two network segments for all the departments located at this site. The first network segment includes corporate and finance department. The second segment includes MFG, MTLS and QA departments respectively. The third network segment includes laser jet printers. The fourth segment indicated as a gateway switch on the network diagram indicates another network segment connecting all the servers located at the site. The fifth segment indicates the factory floor. Lastly, the sixth segment indicates WAN segment including devices that are required to communicate with the WAN interface. Pontiac is responsible for generating custom-based plastic parts. After analyzing the network diagram, the site has total four network segments. Three out of four are segmented to provide network services to employees working on the site. One of the three network segments is proving connectivity to the WAN devices. The fourth network segment is connecting the workstations of the manufacturing floor. In the end, the remaining site that is the research and development facility, which is also the head office of Riordan manufacturing, consists of total five network segments. The first two segments are providing network services to four different department including Corp, Marketing, Finance and HR. The third segment is connecting color printers. The fourth network segment is connecting a plotter on the network. Lastly, the fifth network segment is connecting VoIP data router. Issues of Tree Topology As there is no centralized provision of services, it is difficult for the network engineers to tackle issues related hardware, software and network services. Physical intervention is required as the hub backs up each network segment, if the hub become nonoperational, the workstations of the entire department becomes unavailable on the network. Moreover, it is not necessary that each network segment is using the same cabling scheme (Chapter 5: Topology). Due to compatibility issues, cross cabling or straight cabling is required, consequently making difficult for network engineers to troubleshoot network issues. However, in the current network diagram, a standardized cabling scheme is implemented to ease network management issues. Moreover, due to separate network segments on the network, some network segments may become vulnerable to threats, as network administrators do not have a centralized access to the network devices. These considerations must be analyzed during the network design stage of an organization. Network LAN Topologies Network topologies are essential before implementing a network as per requirements of an organization. Topology is a framework defining the arrangements of every object on the network. This includes workstations, network components, servers, WAN devices and many more. There are total five topologies to design a computer network. However, all of these five topologies shares certain factors. Each topology demonstrates disadvantages as well as advantages that will be discussed further. The five different topologies are illustrated below: Star Topology Star topology is recommended for the wired local area network. It is the most widely adopted topology. The star topology supports the centralized provision of network resources and services. The support staff can manage the network administrative and troubleshooting tasks centrally. Star topology helps to implement centralized security architecture for improved and enhanced security of the network. The network implementation cost can be saved by provisioning the core systems located centrally. The security controls and backup systems are also located centrally for better troubleshooting and management. Ring Topology The ring topology shares the same network cable to connect workstations, servers, printers and peripheral devices on the network. The gateway for data exchange is the hub that is based on multi station unit or multi station access unit. The functionality of exchanging data on the network includes a token ring that passes via each node on the network. The required data is encapsulated in the token ring, which delivers the data in an orderly manner to the recipient. Bus Topology The bus topology shares a single communication channel via all the nodes available on the network. However, before transmission, collision detection and multiple access (CSMA/ CD) sense the current activity on the bus, in order to prevent collision between the two communication channels. If CSMA /CD sense that the data is already available on the bus, then it waits and counters checks in order to transmit data on the network, when the bus is free. Tree Topology The tree topology is based on two topologies i.e. star topology and bus topology. Moreover, tree topology facilitates the network administrator to expand the network easily. However, if the network expands, it becomes more difficult for the network engineers to manage the network. Recommended LAN Topology Recommended LAN topology for Riordan Manufacturing is a star topology. As star topology shares many advantages, the most prominent one is the centralized administration and monitoring of the network. Moreover, star topology provides high data speeds along with easy installation of cables. Any component on the network can be removed or plugged in without any interruption. Likewise, centralized administration facilitates network administrators and engineering to detect issues and faulty components. In the current network design of Riordan Manufacturing, hubs are deteriorating network performance. As they can only operate on the maximum data transmission speed of 10 Mbps and copy data files to the designated ports, files that are larger will take time and may congest the network. However, cost of the hub is low as compared to a switch, it may affect the performance of the network as well the overall performance of Riordan Manufacturing. On the other hand, switches can improve network performance significantly. As switches can learn the MAC address of the sender, they create a management information base for storing all the MAC addresses of network nodes. This will eliminate the time taken by the switch to identify and learn MAC address of the sender. Moreover, switches can provide the overall network usage along with statistics related to access policies via the network. Switches only share a disadvantage of a high cost as compared to hubs. Wide Area Network The wide area network connects two or more remote offices that are separated region wise, country wise and even continent wise. The current WAN of Riordan Manufacturing is based on T1 links that are terminating on an external CSU / DSU. Subscribed bandwidth for Albany is 256 kbps and 256 kbps committed information rate (CIR) for emails. Moreover, bursting is also supported up to 1.5 Mbps o CIR. The plastic fan plant in China is also equipped with T1 that is terminating directly on the router. The custom plastic parts plant located in Pontiac is similar to the Albany site that includes a 256 kbps bandwidth for Internet, and 256 kbps committed information rate (CIR) for emails. The connection is terminating on an external CSU / DSU with a router on the backbone. Headquarter at San Jose is also demonstrating the same WAN architecture that is similar to the site located in China. Proposed WAN Architecture Organizations spent massive funds to purchase advanced security appliances and hire security professionals, only to ensure the protection of the network. As over the last two decades, network security has gained significant importance due to increase in a number of threats and vulnerabilities. There is a requirement of monitoring the network on a continuous basis for possible threats and vulnerabilities. In order to establish a secure and robust WAN architecture, three factors need consideration. The first factor is security. As per the current WAN architecture, there is no adequate security and the network is vulnerable once the firewall is bypassed. Incorporation of an Intrusion detection system (IDS) is compulsory as it will penetrate deep in the network and detect unknown activities related to unauthorized access, viruses and hacking. There are many types of IDS, the recommended IDS for is an anomaly based IDS. Anomaly based intrusion detection system is based on data driven methodology that complies with data mining techniques. The functionality of an anomaly based IDS involves in the creation of profiles associated with normal behavior and activities within the network. If any unknown activities initializes that are not similar to the normal profiles, is considered as anomalies or attacks. Moreover, the normal routines of normal profiles are also monitored, if they also exceeds from their given boundaries, they are also considered as anomalies also called as false positives. An efficient anomaly based IDS may extract results containing high detection success rate along with low false positive rate. Moreover, these systems are categorized in to various sub categories including data mining, statistical methodologies, artificial neural networks, immune systems and genetic algorithms. Among all of these, statistical methods are more commonly used for detecting intrusions by finding out any anomaly that has initiated within the network. The second factor is the WAN architecture. The current WAN architecture is based on T1 that only supports 1.5 Mbps and is not cost effective as compared to other WAN technologies. Moreover, there is a requirement of physically installing the cable that may cause disruptions in business operations. Whereas, DSL can provide a significant advantage over a T1 as it operates on a telephone line along with higher bandwidth rates. Moreover, DSL is a ‘cost saving’ option due to its low rates. Likewise, DSL operates on two modes i.e. symmetric DSL and Asymmetric DSL. Some of the advantages of a DSL connection over a T1 are as follows: Higher Availability in rural areas Low bandwidth cost Due to its high speed, VoIP services eliminates lagging Provides Unlimited Downloads Splitter provides an extra telephone line as well as DSL service DSL routers can provide Wireless connectivity as well DSL routers have an internal Firewall DSL routers have a built in firmware supporting access control lists and filters. Network Protocols and Rationale In the current network scenario, the following data and voice protocols are operational: TCP Transmission control protocol ensures the reliable delivery of data on time. If a data packet fails to reach destination, TCP recalls for the missing packet. UDP User datagram protocol is a connection less protocol that is configured to optimize ‘real time’ applications. However, UDP does not ensure reliable delivery of data. In the current network scenario of Riordan Manufacturing, UDP supports the following operations: File transfers DNS queries FTP File transfer protocol provides convenience for transferring files on the Local Area Network (LAN) as well as on the Wide Area Network (WAN). As there are total four branch offices, file transfer protocol facilitates to transfer files via Internet. Employees may have a requirement to access files from ERP or data servers located at each branch office. HTTP Hyper text transfer protocol (HTTP) displays information related to web pages on the browser as Riordan Manufacturing is maintaining an ERP, the web pages are demonstrated on the web browser by HTTP. HTTPS Secure Hyper text transfer protocol (HTTPS) also servers the same purpose except adding security features by incorporating Secure Socket layer (SSL). HTTPS will serve Riordan Manufacturing for making secure online data transmissions. VoIP Voice over IP facilitates employees of Riordan Manufacturing to make cheap calls and fax to their relevant staff. Moreover, it also provides better customer services with a ‘cost effective’ solution. Advantages and Disadvantages of Adopted Protocols Advantages Disadvantages TCP Ensures Delivery on time, Request for missing packets, built in debugging As TCP relies on operating system to operate, issues arise if an operating system becomes corrupted. UDP Makes more than one connection to receive data and ensures fast delivery of data Do not ensure reliable delivery of data due to no acknowledgment. Moreover, it also not ensures timely delivery of data packets. FTP Facilitates large file transfers and easy to organize file transfers. As FTP is not a secure protocol, it allows space for brute force attacks, packet sniffing and spoof attacks. HTTP It is easy to code in HTML as compared to other programming languages. As all the authentication details are available in the HTTP header, routers can easily manage authentication criteria. Authentication information available in the HTTP header can be easily retrieved by hackers as the information is nor encapsulated. HTTPS HTTPS operates on the same mechanism, except its integration with Secure socket layer. HTTPS encrypts all the information and transmits it in a secure tunnel. An SSL certificate expires in a small period. Moreover, integration of HTTPS in a website is a complex and time-consuming tasks. VoIP VoIP provides ‘low cost’ communication with exceptional voice quality. Moreover, trunks can be created on a DSL connection to divide them in a dedicated VoIP channels. Once the VoIP server goes down, there is no service for even emergency calls. Moreover, the quality of voice depends on Internet bandwidth. Network Security Currently, Pontiac and Albany sites do not have any network security appliances in place. The networks of San Jose and China sites have installed firewalls for the overall network protection. A computer network Firewall is defined as “The primary method for keeping a computer secure from intruders. A firewall allows or blocks traffic into and out of a private network or the user's computer. Firewalls are widely used to give users secure access to the Internet as well as to separate a company's public Web server from its internal network. Firewalls are also used to keep internal network segments secure; for example, the accounting network might be vulnerable to snooping from within the enterprise” (Zwicky, Cooper, & Chapman, ). E1 connections are terminating on the firewalls that are connected to routers. However, Pontiac and Albany are directly connection to the head quarters i.e. San Jose, if one of the networks at San Jose is compromised, they can easily penetrate to other sites of the company. Network Security Requirements In order to implement adequate network security architecture, each site of Riordan Manufacturing will be examined separately. Albany Network There are no network security appliances installed within the network. As per the network diagram, Internet connection is terminating on the Kentrox Datasmart 658 CSU / DSU. This concludes that in spite of having an Internet access, there are no network security devices to detect and eliminate threats. China Network Network in china is only equipped with a firewall. The firewall is responsible to detect and eliminate network threats along with restricting access to unwanted websites. Currently, hacking has become ever more advanced and firewalls can be bypassed easily. Pontiac There are no network security appliances for protecting the network i.e. the network is vulnerable to hackers, intruders, viruses, spywares, adware, root kits and many more. Internet connection is terminating on the Black box V35 MT100A-35 R2 CSU/DSU, apart from the model, similar to the Albany network. San Jose As San Jose is the head quarter, data from all sites is stored and maintained here. It is vital to protect the network of this site. The current network only illustrates a firewall in place that is responsible to handle network threats as well as restricting access to unwanted websites. Proposed Network Security Architecture Albany and Pontiac Networks As the network security architecture of both networks is same, there is a requirement of implementing an ‘IDS’, for continuous monitoring of all the network activities. IDS will provide alerts and warning for possible and potential threats that may disrupt the network services. Moreover, physical security is also essential and the critical information assets for Albany network are Windows NT File / Print Server, Windows NT Exchange Server, RS 6000 IBM AIX, UNIX ERP Server and UNIX MRP II. Biometric access doors are required in order to ensure access of concerned personnel in the server room. Furthermore, IP cameras are required for surveillance of critical assets, in order to ensure their safety, eliminate physical theft of computing and network devices. China and San Jose Network As the network security architecture of both networks is similar, there is a requirement of protecting the network with advanced security appliances. IDS will add value to the current network security architecture as it will constantly monitor network activity and transmit alerts and warning related to threats and vulnerabilities in the initial stages. This will facilitate the support staff to minimize the risk of a security breach at the starting stage. In order to protect critical information assets of the network i.e. NAS Iomega P800M, WIN Network Server, WIN exchange server, and UNIX ERP / MRP Server, physical security protection is essential. Installation of biometric identification on entrance doors may allow only the concerned staff to enter in the server room. Moreover, IP surveillance cameras are also required to eliminate data or physical theft issues. Conclusion After reviewing the network, some of the workstations are outdated and running on significantly low hardware resources. Hubs are demonstrating several network segments on each site of Riordan Manufacturing, creating a risk of disrupting services if any one hub becomes faulty. Moreover, WAN technology is also not up to the mark, as there are ‘high bandwidth’ carriers available now with low cost, supporting applications that are rich in multimedia. Moreover, these carriers can also meet demands of application and protocols demanding ‘high bandwidth’ requirements. Some of the ‘high bandwidth’ private and secure carriers are Domestic Private Leased Circuits (DPLC) and International Private Leased Circuits (IPLC). In order to add value to the network, hubs need to be replaced by switches along with the implementation of VLAN. VLAN may provide an enhanced security framework for the inbound network and will divide the flow of inbound digital transmission in to separate channels for each network. This may eliminate risks of IP broadcast and denial of service attacks. Furthermore, an addition of IDS will secure the protection of the network inbound and outbound, due to its continuous sensing capability. In addition, for physical security measures, installation of IP surveillance cameras and Biometric identification system is recommended. References Chapter 5: Topology Retrieved 6/17/2011, 2011, from http://fcit.usf.edu/network/chap5/chap5.htm Zwicky, E. D., Cooper, S., & Chapman, D. A.Building internet firewalls Beijing ; O'Reilly, c2000. Read More