Exercise 4: Virtual private networks

Describe the IP Protocol. What is DNS?

IP stands for Internet Protocol. It is a protocol on network layer and responsible for packet delivery from host to host. It is a connectionless and unreliable protocol for data transmission (Hollinger, 2001). It represents the host and network addressing. It is an unique identifier for the computer to the network for data and information transmission. When a computer connects to the internet, a unique IP is required.

There are two version of the IP Protocol, version 4 (IPv4) and version 6 (IPv6). The IPv4 uses 32-bits to address itself and according to the Brendan (2009), it supports more than four billion unique addresses. As the internet population growth during the years and each computer required to have a unique IP address for direct internet connection, the number of the IP address reduces. The IPv6 provides two to the one-hundred twenty-eighth power of unique addresses which is enough for the future growth of the internet population. (Brendan, 2009)

DNS stands for Domain Name System. It is a service on the top of the Internet Protocol. The DNS is used to resolve the name entered at browser to IP and vesa visa. DNS is used because user requires meaningful name to browse the internet instead of browsing a website by entering non-meaningful IP address. (Brendan, Webopedia 2009)

Describe the TCP protocol. How is it related to the IP protocol?

TCP stands for Transmission Control Protocol. It is a protocol on transport layer. The TCP is connection-oriented and reliable protocol to make the completeness of data transfer.

A three way handshake and virtual connection is made before transmission. With it packet structure, the lost of packets by lost or error in connection can be detectd by its sequence number and request number. The corruption of the packet also detected with the checksum of the segment in TCP packet (Hollinger, 2001).


Figure 1: TCP segment structure (Hollinger, 2001)

What do you know about building e-business application as an Intranet, Extranet, Web portal, B2B, B2C or Virtual Private Network (VPN)? Find some examples on the web.

Intranet is a network can be accessed by authorized personnel within an organization only such as employees. With the use networking technologies such as TCP/IP, the user shares the current informaiton such as calendars, sending internal emails and even access the employee contact information. (Randolph)


Figure 2. Intranet (Randolph)

Extranet is intranet network that mapped to the internet or specificed private network. (Wikipedia)

FedEx
http://customcritical.fedex.com/us/owneroperator/signin.shtml

Web portal is a managed online system providing different kind of service via single point of access. It usually manage the information into customable channels for users to subscribe.

HKU SPACE
http://soul.hkuspace.org/

CSU
http://my.csu.edu.au/

According to the wikipedia, B2B is Business-to-Business that involve transactions between manufacturer and a wholesaler or between a wholesaler and a retailer. B2C is defined as Business to Customer that usually involve single transaction between them.

Vitual Private Network uses the public network for transferring information with encryption for security purposes.

What role can VPN play in business-to-business e-commerce?

Vitual Private Network play the role for security in business-to-business in e-commerce. Since it uses encryption such as IPsec, hashing techniques, DES and AES for validation and data transfer, the security of the information is enchanced.

Furthermore, there is a tunnel mode in VPN that allows to form a connection like a leased line in the internet between them, the capturing of the data stream from someone else is minimized. (Wikipedia)


Reference:
Webopedia (2009), IP address, Retrieve 25 March 2009 from http://www.webopedia.com/TERM/I/IP_address.html

Brendan M.G. (2009), What is IP or Internet Protocol?, Retrieved 25 March 2009, from http://www.wisegeek.com/what-is-ip-or-internet-protocol.htm

Hollinger D. (2001), Internet Protocol: The IP in TCP/IP
Retrieved 29 March 2009 from http://www.cs.rpi.edu/~hollingd/javanetprog/notes/tcpip/tcpip.ppt

Wikipedia (n.d.), Virtual private network, Retrieved 30 March 2009 from http://en.wikipedia.org/wiki/VPN

Randolph B. (2004), Intranet v/s E-commerce sites, Retrieved 30 March 2009 from www.ischool.utexas.edu/~i385grb/Intranet_vs_E-commerce.ppt

Wikipedia (n.d.), Extranet, Retrieved 30 March 2009 from http://en.wikipedia.org/wiki/Extranet

SearchEnterpriseWAN.com (4 March 2009), extranet, Retrieved 1 April 2009 from http://searchenterprisewan.techtarget.com/sDefinition/0,,sid200_gci212089,00.html

Indiana University (2 March 2009), What is a web portal?, Retrieved 1 April 2009 from http://kb.iu.edu/data/ajbd.html

webopedia.com (7 June 2006), intranet, Retrieved 1 April 2009 from http://www.webopedia.com/TERM/I/intranet.html

Dennis P. G. (n.d.), Finding Your Way Around E-commerce, Retrieved 1 April 2009 from http://www.intranetjournal.com/features/Ecommercetut.html