Question

it is required implement 40-Gbps computer network to connect the four building (MB,CB,LB,NHB) in the faculty of engineering given .each building three teaching halls distributed in three floors and it is required to install an independent network with 24 outlet points in each halls six servers will be used to provide the required local storage for each building while a SAN storage and control room will be in communication building(CB).

a) design the required computer network, state the function of each device and specify the typyes of cables you will use and justify your selection

b) explain your solution in terms of network diameter ,bandwidth aggregation and redandant links

Answer 1

Unshielded twisted pair (UTP) is a widely employed cable and it is well suited for this purpose. It uses a high-speed cable and the cable contains four pairs of wires inside the jacket in which each pair is twisted such a way that the number of twists per inch varies so that it can preclude interference from adjacent pairs as well as other electrical devices. Higher the twisting, greater the supported transmission rate as well as cost per foot. The standards for the Unshielded twisted pair (UTP) can be found at EIA/TIA (Electronic Industry Association/Telecommunication Industry Association) which contains six groups of wire.

Groups of Unshielded Twisted Pair as per EIA/TIA:

Group	Rate	Suitable Device
1	1 Mbps	Voice Only (Telephone Wire)
2	4 Mbps	LocalTalk & Telephone
3	16 Mbps	10BaseT Ethernet
4	20 Mbps	Token Ring
5	100 Mbps (2 pair)	100BaseT Ethernet
	1000 Mbps (4 pair)	Gigabit Ethernet
5e	1,000 Mbps	Gigabit Ethernet
6	10,000 Mbps	Gigabit Ethernet

Network Diameter

A hierarchical network topology is recommended for the given problem and it is important to consider the network diameter, therefore diameter is a measure of distance, however, in our case, we will measure the number of devices in which a packet has to cross to arrive at its destination. It is recommended to lower the network diameter low for predictable latency between devices.

In our case, if MB communicates with LB, there should be six interconnected switches between MB and LB, therefore the network diameter would be 6. Degree of latency would be produced by each switch as well as each switch should compute destination MAC address of the frame, check its MAC address table, and forward the frame out the appropriate port.

In the three-layer hierarchical approach, network diameter can predict the number of hops between the source as well as destination devices.

Bandwidth Aggregation

Bandwidth aggregation considers the particular bandwidth needed for each part of the hierarchy. In our case, link aggregation should be created which can support multiple switch port links to be integrated for greater throughput between switches. For this purpose, EtherChannel by Cisco which is a proprietary link aggregation technology can be employed.

Redundancy

Deploying redundant links can increase the cost. In our case, it is unlikely to deploy redundancy at the access layer considering the cost as well as limited features in the devices, however, if needed redundancy can be created and integrated into the distribution as well as core layers of the network.