Network Design for UMUC Branch Office - Term Paper Example

? Network design Network design Provided requirements The project seeks to upgrade the network of UMUC branch office located in Mannheim, Germany. The present system is rather fragmented with each department having its own network with its own DSL connection. To access resources, students and faculty members have to access each department via the Internet to access resources. All have added computers using switches and repeaters. However, the unplanned expansion has strained system capacities. As a result, system users face a number of challenges including delays, frequently dropping connections, or not being able to connect at all. Additionally, at the moment, the departments lack secure networks and hence prone to frequent virus attacks. The director of the campus is seeking to improve security, raise network bandwidth, and also consolidate the multiple LANs into one campus network whilst keeping costs minimal. The major problems identified in the current network include: High rate of collisions Slow speed due to a large broadcast domain High administrative cost due to a lack of centralized network management Lack of backup WAN connectivity Lack of data backup on servers Inadequate network security Use of manually assigned IP addresses The campus building is 40 years and 2-storeyed. Its dimensions are as follows; Length: 240 Feet Width: 95 Feet Height: 30 Feet Workstation Placement Number of Workstations Users Total WS 6 Instructional Computer labs 21 WS Student and Instructor 126 WS (based on 20 WS for students and 1 WS for instructor on each lab * 6 labs) Student Computer Lab 30 WS Student 30 WS 6 Offices 1 WS Staff 6 WS 1 Admission office 5 WS Staff 5 WS Library 10 WS Student 10 WS Library 5 WS Staff 5 WS 4 Instructional Classrooms 1 WS Instructor 4 WS Total Server ? Staff To be determined by students Network Connecting Devices ? IT Staff To be determined by students Printers ? Staff To be determined by student Printers ? Instructional To be determined by student Definition of the subnet The following subnets are adopted in the design: Each lab is to have a subnet, totaling to 6 subnets The student computer lab is to be assigned a subnet of its own Staff members in all the offices will be assigned a subnet Students in the library will be assigned a subnet One subnet will be assigned to the instructors in the lecture rooms The two servers, one of the first floor and the other in the second floor will share a subnet Definition of the network address, subnet mask, and available IP addresses to be used by the computers or devices. Network Address: 10.15.0.0 Network Mask: 255.255.0.0 At least 11 subnets are required, implying a need for at least 31 addresses for each subnet. The closest number of addresses offered by a subnet is 32. Nonetheless, taking into consideration the fact that all subnets require a network address and a forecast address, 30 is the appropriate number of IP addresses. Given that the student computer lab requires a minimum of 31 addresses, 64-address subnet is required. Considering availability of a whole class B network, constituting a Class A address and a class B mask, it is possible to anticipate growth on the devices used in each classroom / office and make use of a whole Class C network for every subnet. This will allocate each subnet in 256 addresses whereby 0 would is to be the network address while 255 will be the broadcast address. This leaves 254-subnet IPs available for use. Proposed Subnets: Range 6 Instructional Computer labs 10.15.0.0/24 Addresses 10.15.0.1 - 10.15.0.254 10.15.1.0/24 Addresses 10.15.1.1 - 10.15.1.254 10.15.2.0/24 Addresses 10.15.2.1 - 10.15.2.254 10.15.3.0/24 Addresses 10.15.3.1 - 10.15.3.254 Student Computer Lab 10.15.10.0/24 Addresses 10.15.10.1 - 10.15.10.254 Staff members in all offices 10.15.20.0/24 Addresses 10.15.20.1 - 10.15.20.254 Students in the library 10.15.30.0/24 Addresses 10.15.30.1 - 10.15.30.254 Instructor’s on the 5 lecture rooms 10.15.40.0/24 Addresses 10.15.40.1 - 10.15.40.254 Servers on first and second floor 10.15.100.0/24 Addresses 10.15.100.1 - 10.15.100.254 Physical Network Design: Topology: an extended star (tree) topology is chosen for the design. Appropriate network media to use: The most appropriate network media for use and hence preferred is CAT6 STP. Appropriate network connecting devices: the design will incorporate a fully routed network to ensure that all the subnets are connected to two routers. All computers, servers, as well as other devices are to be connected to switches. The switches are located in each room. Two routers are used in the design, one is located in the library and the other is in the student’s computer laboratory ensuring that each floor has a router. A wireless access point is available in at the student’s lobby area. Also available is a single Internet Firewall on the room where the first floor’s server is located to allow internet access connection to T1 modem. There is also another firewall meant to secure against unauthorized access of the server by students or staff (this creates a DMZ for the servers). 4. Physical layout of the computers on the floor plan. 5. List of additional servers or network devices needed to implement the network. Ideally, the following servers should be implemented; A pair of Access Control Servers such as MS Domain Controllers to regulate access to user account resources Database server, preferably SQL or Oracle, with a number of databases for inventory control of information such as library information, IT information as well as Students and Staff population data. A DB server in a cluster for elevated availability is recommended A number of file servers in cluster for storage of user files with increased availability. External site web server Intranet web server Document management system Remote access server to allow staff members and students access information from locations external to the campus. DHCP server with adequate capability for management of all subnets. Internal DNS servers to resolve server name issues. Proxy server for minimization of outgoing traffic through highly used content caching Infrastructure/inventory management server for IT to regulate devices, hardware inventory as well as software/software updates. Image servicing server for deployment of images to new computers as well as reinstallation of computers suffering software issues. Justifications for the described network design The selected subnetting address scheme is ideal for the scenario due to its logical separation of computers between students, staff members as well as the servers. The design also has provisions for future expansions. Additionally, based on the chosen topology, CAT6 STP is the most appropriate support media due to its ease of construction, high reliability, provision for elevated speeds, ease of concealment and management (flexibility), as well as ability to effectively bar interference. The caveat for such media is that the media’s maximum length is restricted to 328 ft. (100m) for a single patch. However, the design ensures that no single patch gets close to the media’s length limit. Other than flexibility, availability, and scalability, the chosen topology allows for distribution of computers in nodes which correspond to network address scheme and hence minimize unnecessary traffic/broadcasts. The topology is also most appropriate for the proposed design layout. Additionally, the proposed network design allows for development of a fast, reliable, and secure network. The switches further allow intelligent packet distribution minimizing inappropriate traffic between subnets whilst also offering local connectivity when there is some interruption in a segment. Additionally, the firewalls permit security internal and external threats. The two firewalls included result into server’s DMZ to function with minimal exposure. On the other hand, the routers make it possible to have a fully routed network. Given that different subnets are used, there is a need to have a means to route packets from and/or to the appropriate networks. Routers location at the library and student’s computer lab allows avoidance of the possibility of segment requiring breaking the earlier stated, 328 feet limitation associated with the chosen CAT6 cable. Additionally, the wireless AP is located on the student’s lobby area ceiling to facilitate better signal reception while at the same time allow close proximity to the Student Computer Lab. A TI modem is required in order to link the T1 line to local network. To offer security to internet threats, a firewall needs to be connected to the mentioned modem to operate as internal network’s gateway. In order to build DMZ to secure servers from external and internal threats, there is a need for another firewall to be located between the system servers and other components of the network. Network Diagram: Figure 1: Library staff network layout Figure 2: Instructional lab layout Figure 3: Instructional classroom layouts Read More