Question: The question to answer from the report below: As communication on the

Question

Question: The question to answer from the report below: As communication on the Internet is essential. We h...

The question to answer from the report below: As communication on the Internet is essential. We have to select and fully justify the type of internet access you propose to have for this company. This must be scalable to allow for future growth and needs. The Point of Presence (POP) is located at the Perth CBD office.

note: Internet Access for the entire company, the Point of Presence (POP), is through the Perth CBD office. This connection should be sufficient for all current users, and scalable to allow for the expected increase over the next 3 years.

The report: is Coal Corporation is starting a mining operation 30km north of the town of Northram, Western Australia (hereafter referred to as remote site). Coal is also setting up an office in Perth CBD. Coal had tasked up with setting up their networks at both sites. Coal wants to set three local area networks (LANs) at their remote site. One network for the finance department, one network for the company executives and one network which provides anyone with company credentials ubiquitous connectivity in the area. The first two networks need to be secure. For their CBD offices, Coal requires four networks. Three networks are the same as for the remote site with an additional network for the sales department. There is also a server farm at the CBD site consisting of four servers. There needs to be a ‘fast’ connection between the CBD and remote sites. Coal is also exploring other mining projects. Therefore, Coal wants a network which allows for 30% expansion in the next three years.

Explanation / Answer

One of the hallmarks of networks that have power-law degree distributions and that are generated

according to any of a number of different probabilistic mechanisms (

e.g.,

preferential attachment [13],

random graphs with a given expected degree sequence [30], power-law random graphs [3]) is that they can

be shown to have a few centrally located and highly connected

hubs

through which essentially most traffic

must flow. When using these models to represent the router-level topology of the Internet, the presence

of these highly connected central nodes has been touted the Internet’s “Achilles-heel” because network

connectivity is highly vulnerable to attacks that target the high-degree hub nodes [5]. It has been similarly

argued that these high-degree hubs are a primary reason for the epidemic spread of computer worms

and viruses [112, 122]. Importantly, the presence of highly connected central nodes in a network having

a power-law degree distribution is the essence of the so-called scale-free network models. They have

been a highly popular theme in the study of complex networks, particularly among researchers inspired

by statistical physics [4], and have fuelled the rise of a new scientific discipline that has become known

as “Network Science" [12]. In the process, they have also seen wide-spread use among Internet topology

researchers.

However, as the general fascination with and popularity of network science in general and scale free

network modeling in particular grew, so did the arguments that were voiced by Internet researchers and

questioned the appropriateness and relevance of the scale-free modeling approach for studying highly-

engineered systems such as the Internet’s router topology. In fact, at around 2010, when the number

of publications in the area of network science reached a new height, the number of papers that were

published in the networking research literature and applied scale-free network models to describe or

study router-level topologies of the Internet was close to zero. This begs the question “What happened?”,

and the answer provided in the next section is really a classic lesson in how errors of various forms occur

and can add up to produce results and claims that create excitement among non-networking researchers,

but quickly collapse when scrutinized with real data or examined by domain experts

Related Questions

Navigate

• Browse (All)
• Browse Q
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.