Exercise 3

1. Explain DNS and DHCP and how does DNS differ fom DHCP configuration?

DNS (Domain Name System)
On the Internet, each computer needs to have an unique address to be located. It’s just like a postal address for an individual. For the computer itself, an IP address consists of 4 bytes (32 bits) of decimals, and separated by dots are used. E.g. 208.77.188.166. These numbers are good for machine, but not good for human to memorize. Therefore, a ‘meaningful’ name called DNS is used to map the IP address to a human memorized-able name. e.g. www.yahoo.com. DNS is a naming system and it is maintained central at Internet Corporation for Assigned Names and Numbers (ICANN).

DHCP (Dynamic Host Configuration Protocol)
DHCP is the computer protocol for the computers to get an IP address when it is connected to the network. The computer needs to be configurated as a DCHP Client and the machine who assign the IP address is called DHCP Server. In case the DHCP Server is not present, or for some reasons a specific computer wants to have a fixed IP address (e.g. a file server) then manually assign the IP address is required. (we call it a static IP address)

2. Why it is important in your online business application to use static IP address rather than have it dynamically assigned?

To have static IP address can have two main benefits: (1) The translation is more effective, so the response for the visitor is better. (2) It is more secure than using a DHCP that might route you to somewhere fake web sites.

3. What role can the following play in business to business e-commerce
a) Virtual Private Network (VPN) or Grid computing services?

The VPN is a method to provide additional security on top of a communication network and make the communication between two ends looks like ‘private’. (or technical term called ‘Tunnel’). The VPN encapsulates the traffic and data to avoid eavesdropping. For e-commerce, VPN improves confidence for monetary transaction like credit card information. So it helps to boost the e-commerce without the fear of losing confidentiality.

b) Next generation of wireless mesh network

First, a wireless mesh network (WMN) can be defined as ‘is a communications network made up of radio nodes organized in a mesh topology. Wireless mesh networks often consist of mesh clients, mesh routers and gateways. The mesh clients are often laptops, cell phones and other wireless devices while the mesh routers forward traffic to and from the gateways which may but need not connect to the Internet.’ (Wiki, 2010).

From a study conducted jointly by Deutsche Telekom Laboratories and University of Napoli, the existing mesh network technology ‘shows the feasibility of providing WiFi coverage to large areas, such as entire cities. But not more. At a technical level, current mesh networks are far from efficient’. (Karrer, P. & Pescape, A., 2009). With the next generation of wireless mesh network, all these areas would be improved. Then more people could access with confidence through the next generation of WMN. Hence the potential e-commerce market would be enlarged.


References

Karrer. P., & Pescape. A. (2009). 2ndgenerationwirelessmeshnetworks: technical, economical and social challenges. Retrieved from http://www.deutsche-telekom-laboratories.de/~karrer/papers/FGCN07.pdf on 11 March 2010

Wiki. (2010). Wireless Mesh Network. Retrieved from http://en.wikipedia.org/wiki/Wireless_mesh_network on 11 March 2010

c) Cloud or Social cloud applications

Cloud applications are the applications that offered by the giant ‘cloud’ service providers like google, amazon and IBM. With the traditional model, a company wants to enter into the e-commerce, they need to set up their own IT department, develop their e-commerce application. But with the cloud applications, they don’t need to start everything from scratch. There are bunches of application and software that can be used right away. With the SaaS concept (Software as a Service), the small or medium company that originally do not have the capability can now easily to deploy e-commerce. Therefore, the Cloud applications would lower the threshold and help more companies join the e-commerce world.

4. If clouding computing is the “black box”, the grid computing is a component as the “white box”

Explain what you interpret about that statement.
Most time we heard about cloud computing are scalability, pay as you use, utility computing…etc. The focus of ‘cloud computing’ is the benefits that can be offered from the service provider like a black box, and the users no longer need to worry how to maintain the IT department.
The grid computing is ‘a form of distributed computing whereby a “super virtual computer” is composed of many networked loosely coupled computers acting in concert to perform very large tasks.’ (Grid Computing, 2010) The grid computing is more on the technology side, so it can be seen a component as the white box of the cloud computing.


References
Wiki. (2010). Grid Computing. Retrieved from http://en.wikipedia.org/wiki/Grid_computing on 11 March 2010