Exercise 4. Virtual Private Networks

1. VPN which stands for Virtual Private Network is private network constructed within a public network infrastructure (Ferguson & Huston, 1998)

Coming from the telecom domain of expertise. VPN in the older days could mean "corporate networks" and "environment" that has to be end to end secured - physical layer. With the advent of packet data swtiching networks, information can be "wrapped" in a virtual envelope, with address information, and be sent via various routes with network protocols such as the IP protocol. Older protocols are like the X.25 standards in data communications or X.400 for mail messaging. These are pretty much old school but some are still used today. Datapac for example is a common data network used extensively in HK during 1980's to 2000's.

DNS on the other hand is Domain Name Servers. IP addresses is in the form or x.x.x.x and name servers are needed to reroute pneumonic names such as google.com to a traceable table of ip address and eventually reaching the physical location of the server that serves the page of google.com. DNS is a complex hirearchical system of trust and labelling system in a lay man's terms.

2. TCP protocol - Transmission Control Protocol. With the design of IP, being packetised and kept in an virtual envelope, each packet of information and data will have to be routed with the given information (as headers, trailers) as to where it should go. TCP allows the efficient parsing of the address information in order to reach its destination. TCP and IP are very closely knitted terminology and data protocols because they are complimentary. IP is related to packetising data and information and TCP is related to the transport layer of the packet data.

3. E-Business applications is a very abstract term; it gets abused a lot. Sometimes, people think by owning a domain name, a email account, a website is automatically a e-business capable. In my belief, to be classified as a genuine e-business application, the convenience and output must be greater than the effort of inputs and that the application must solve a problem that otherwise cannot be solved by existing means. Ebay is a classic example, Paypal is another example, Youtube is also another example but not nytimes.com

Intranet - accessing corporate network and resource using IP protocol inside a building or site
Extranet - accessing corporate network and resources using IP protocol outside a building or site or remotely

Web portal - a website which plays the role of aggregator and repository of many information feed and content. eg. http://nytimes.com

B2B - Busines To Business websites ( This B2B word brings me tears. I once invested as an angel investor US$20K in a business called B2Bweb.com in 1998-2000. It literally vaporises !!); however success in operating B2B marketplace has been better for Alibaba
(BeijingReview, 2007) debuted at listing at Hong Kong Stock Exchange eg. http://Alibaba.com

B2C - Business To Consumer websites (I did make some money online running B2C online stores before selling the business when in Canada, I have no negative sentiment towards this B2C name). eg. http://www.eToys.com

There are also C2C websites. C2C is like ebay or china's taobao (BejingReview, 2007), and kijiji type of classifieds adveristing websites.

4. With respect to VPN. Most of today's business applications and online businesses are running some form of VPN - by resources sharing of secured sessions; session based i.e. not link based. In the most simplest form, it is as simple as using https://xyz.com of the payment gateway or login session to a corporate network. In theory, the global network or the Internet that we use today is in fact a global VPN being sliced and diced into "sessions" of VPN.

In the past, there are many international value-added network business. AT&T VANS, Infonet, Sprint IVAN, BT IVAN and NTT, GlobalOne, etc. These international data networks are slowly moving aways from their own infrastructure (eg. T1/T3 link based network) to IP based networks. In summary, I would say that TCP/IP is now the most important network protocol replacing X.25 in VPN.

Reference:

1. Ferguson. P & Huston. G (1998) . What is a VPN ?
Retrieved from http://campus.murraystate.edu/tsm/tsm340/vpn/vpn.pdf

2. Bejiing Review (Aug 9, 2007) B2B Pioneer a Millionaire Maker
Retrieved from http://english.beijingreview.com.cn/print/txt/2007-08/03/content_71488.htm