Exercise 3

1. Explain DNS and DHCP. How does DNS differ from DCHP configuration?
DNS-Domain Name System
Every computer on the Internet has a unique address – just like a telephone number – which is a rather complicated string of numbers. It is called its "IP address”. But it is hard to remember everyone's IP address. The DNS (Domain Name System) makes it easier by allowing a familiar string of letters (domain name) to be used instead of the numerical IP address (“The domain name system”, n.d.). So instead of typing 192.0.43.56, you can type www.example.com. The DNS is a service that provides a mapping between the name of a host on the Internet and its numerical address. DNS is essential to the functioning of the Internet.
DHCP-Dynamic Host Configuration Protocol
DHCP is a method to automatically and dynamically assign difference IP addresses to devices in a network. The main purpose of DHCP is to help an individual computer to obtain its configurations information from the server (DHCP server), actually the server have no ideas about the client until it receive requests from client. DHCP helps to remove the burden of manual works for network administrators. It is very useful for big organizations which have thousands of computers.

References

The Domain Name System: A Non-Technical Explanation – Why Universal Resolvability Is Important (n.d.). Retrieved Dec 27th, 2008 from http://www.internic.net/faqs/authoritative-dns.html

What is DHCP and DNS? (n.d.). Retrieved Aug 22nd, 2009 from http://www.blurtit.com/q614442.html

2. Why is it important for your online business application to use a static IP address rather than have it dynamically assigned?
Using static IP address for online business is important because it offers the following advantages over dynamical IP (Mitchell, n.d.): It helps customers to find your website easily because the name resolution service supports static IP address better. Static IP addresses might give your application a better protection from security threats. It supports VPN.

Reference

Mitchell B. Using Static IP Addresses on Private Networks . retrieved August 22nd, 2009 from http://compnetworking.about.com/od/workingwithipaddresses/qt/staticipaddress.htm

3. What role can the following play in business-to-business e-commerce?

a. Virtual Private Network (VPN) or Grid computing services
Virtual Private Network (VPN) plays an important on in business to business e-commerce because it ensures that data communication between two (or more) organizations is protected by encryption and others security mechanisms and authorized person can access VPN. Therefore, they can communicate fast, secure and reliable (Tyson, n.d.). In addition, VPN helps enterprise to build a more effective extranets in term of cost.

b. Next generation of wireless mesh networks
A wireless mesh network will help all the staffs in an enterprise increasing files and information faster and in a convenient way with much less expense in comparison with traditional wired-networks. For example one staff want to send a file to another, instead of putting it on the server he can send it directly to that co-worker as on instant messenger applications, this will reduce the workload of the server.

c. Cloud or Social Cloud applications.
To have a deep understand about cloud applications, we probably need to come with the definition of cloud computing. Actually it is a bit difficult to have a definition of cloud computing. As defined in searchCloudComputing.com:
“Cloud computing is a general term for anything that involves delivering hosted services over the Internet. These services are broadly divided into three categories: Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS).”
Cloud applications are applications which are provided to users or enterprises on the foundation of cloud computing, Software as a Service in particular. Using cloud applications would reduce the cost of capital expenditure on hardware, software or staffs(of IT department in company) because users or enterprises just have to pay the providers for what they use in other words they pay on demand (“Cloud Computing”,wikipedia). This will help them to concentrate on their core business.

Reference
“How Virtual Private Networks Work?”(Tyson J.) Retrieved August 23rd, 2009 from http://www.howstuffworks.com/vpn.htm

"Cloud computing definition"(n.d) retrieved Aug 28th, 2009 from http://searchcloudcomputing.techtarget.com/sDefinition/0,,sid201_gci1287881,00.html
“Cloud Computing”(n.d). retrieved Aug 29th,2009 from http://en.wikipedia.org/wiki/Cloud_computing

Urquhart J।,A better way to understand cloud computing(2009) viewed Aug 28th,2009 from http://news.cnet.com/8301-19413 3-10152106-240.

4. If clouding computing is the 'black box', then grid computing is a component as the 'white box'. Explain what you interpret about that statement.

In Cloud computing, a user of the service doesn’t necessarily care about how it is implemented, what technologies are used or how it’s managed (Hartig, 2009). So we can think of cloud computing as a “black box”, user just needs to enter an input into that black box and then receive the result without thinking about how it is processed.
Grid computing is the combination of multiple computers from difference domains for the purpose of utilizing un-used CPU processing cycle to process a very huge amount of data, usually for technical or scientific purposes (Davis J.,2008) . For example, SETI project is a well-known grid computing project in which thousands of computers around the world donate their un-used CPU cycles to help searching signals of life from outer space.
As a conclusion the term “black box” can be used to refer to Cloud Computing. On the other hand, in Grid Computing a user posses and control his data and resources. Therefore, the term "white box"can be used to refer to grid computing.

References

Grid Computing(n.d.). Retrieved Aug 23rd, 2009 from http://itmanagement.webopedia.com/TERM/G/grid_computing.html

Hartig K., What is Cloud Computing (2009). Retrieved Aug 23rd,2009 from http://cloudcomputing.sys-con.com/node/579826

Davies J., Cloud Computing or Grid Compting - Which Comes First? (2008) Retrieved Aug 23, 2009 from http://linux.sys-con.com/node/731197

Urquhart J., A better way to understand cloud computing(2009) Retrieved Aug 28th,2009 from http://news.cnet.com/8301-19413_3-10152106-240.html