INTRODUCTION
A network being an interconnection of computing devices in a particular manner for the purpose of resource sharing will be used to interconnect the devices used in the office space at DesignIT. The devices that will be interconnected and shared in the office include servers, computers, antivirus software, internet connection, printers, portable devices etc. A Local Area Network (LAN) is considered a computer network within a building as bound by physical constraints such as coverage range of less than 150 metres. For the purpose of the network design at DesignIT, a LAN will be implemented.
NETWORK DESIGN
Device List
The devices that will be interconnected in the network and those to be used for the connection are listed as follows
6personal computers (PCs)
3 colour laser printers
3 servers
1 router
1 24-port switch
1 wireless router
Optic fibre cables
Registered Jack 45 (RJ-45) plugs
Unshielded Twisted Pair Category 6 (UTP Cat-6) Cables
Office Layout
With respect to the physical space of the office, the server room will house the three servers – the web server, the file server and the small business server. The six computers will be located in the office, reception and the four cubicles with one computer per cubicle.
LAN Design
For the design of the office LAN to cater to the needs of the office using these devices, the logical bus topology will be used to connect all the devices in the LAN. The logical bus topology is arranged such that a central communication channel or line serves as the backbone of the connection of all the other devices on the network.
WAN Connection
The internet connection of the DesignIT office will be implemented using a Wide Area Network (WAN) connection from an Internet Service Provider (ISP) using a Very Small Aperture Terminal (VSAT). This connection provides the source of high speed internet for the office with up to 2Mbps download speeds.
Hardware specifications
The specifications of the hardware devices that will be deployed in the network are considered in details as follows.
Router:The router as a network device is a layer three device of the OSI reference model and interconnects networks. The router serves as the gateway between the office LAN and the Internet in this design. The router directs the data packet traffic that will be allowed into the LAN. This is carried out by filtering incoming data packets into the LAN by IP addresses based on set rules on the kinds of traffic to allow and the ones to reject.
Switch: A switch by default breaks up collision domain in a network. The switch serves as the interconnecting device which is the connection point for other devices that are to be connected to the network. The choice of a24-port switch will cater for all the devices to be connected to the network with room for future network expansion.The switch is more suitable in this arrangement owing to the role it plays in a network as an intelligent frame forwarder to only the ports they are destined for (Tanenbaum and Whetherall, 2011), instead of flooding all the ports with the frame resulting in network traffic.
Wireless router: The wireless router to be used in the network is connected to a port on the 24-port switch. This wireless router provides a wireless access point for portable wifi-enabled devices to connect to the network, especially WiFi-enabled portable devices. The wireless access point will continue to provide network access to devices connected to the network through it as long as the devices are within the broadcast range of the wireless router. This provides a truly nomadic access to the network irrespective of the location of the device.
Printers: The printers used in the office will be connected over the network through the 24-port switch to remove the need to have separate printers for each of the six computers. This arrangement will reduce the overall cost of printing in the office.
Unshielded Twisted Pair Category 6 Cable: All the devices on the LAN will be connected to the Ethernet bus or the switch using the UTP Cat-6 cables. The UTP Cat-6 cables can work in either 10BaseT or 100BaseT standard in full duplex communication mode. TheseCat-6 cables are chosen to be used in this design in order to obtain the best performance that can be offered by shielded twisted pair cable connection.
RJ-45 Plugs: The RJ-45 jacks or plugsare used to terminate the connectionto the UTP Cat-6 cables for easy connection to the communicating devices and the ports of the 24-port network switch.
Cost of Items
Cost of Labour, Equipment and Services
Antivirus software
Firewall
The network firewall prevents unauthorized packets from gaining entry to the network. For this network design, the firewall is implemented as an integral part of the edge router. The firewall consists of a set of rules on the packets to be allowed into the LAN and also based on IP address filtering. Network traffic from any IP address that is blacklisted is not allowed into the network while the traffic from whitelisted IP addresses will be allowed to pass through into the network.
Network Expansion
The future expansion of the office with the addition of new equipment has been catered for in this design. The use of a 24-port switch has enough space to accommodate more devices to be connected to the network in the nearest future.
REFERENCES
Panko, R.R., and Panko, J.L. (2013). Business Data Networks and Security (9th ed.) Boston, MA: Pearson Education, Inc.
Tanenbaum, A.S., &Wetherall, D.J. (2011). Computer Networks (5th ed.) Boston, MA: Pearson Education, Inc.
