E238 Information Systems 12 TEE Data Communications Combo Answers 1997-2000

2000 PART C Extended Answers

28. (7 marks)

Big Bank Electronic Banking Corporation
BIG BANK is an electronic banking corporation with one million customers. BIG BANK headquarters is located in Canberry and there is a branch in each state capital. Headquarters and branches all operate their own networks locally and communicate with each other via the BIG BANK network that extends nation-wide.There is a BIG BANK Call Centre in Canberry to answer customer queries nation-wide.
Customers may request phone and online service 24 hours per day. There are no local branches in the suburbs or in the country because all transactions are completed electronically via automatic teller machines, phone banking and over the Internet. It is almost a cashless society and customers may top up their electronic cash cards using electronic funds transfer at point of sale machines at most retailers and at automatic teller machines.(a) BIG BANK assures its customers that their personal data and banking transactions remain private.
Identify two concerns its customers may have about the storage of their details. (5 lines) (2 marks)

Unauthorised access to their personal details.
Unauthorised banking transactions by other people.Selling of customer details to other corporations for advertising or other business.Accuracy of data (errors)

etc.

(b) Describe two practices that BIG BANK may employ to ensure the security of customer data during storage and transmission on its electronic networks. (5 lines) (2 marks)

Encryption during Internet transactions
Customer passwords (PIN for automatic teller machines)

Different access levels by employees

etc.

(c) Explain why most customers need a modem to participate in online banking from home. (3 lines) (1 mark)

Digital data from customers computers needs to be communicated through the PSTN, which carries analogue data.
The modem is used to modulate the digital signal into analogue signals for transmission along the phone line, and to demodulate the analogue signals back into digital signals at the other end.

(d) Communications media used for data transmission include Fibre Optic cable and Unshielded Twisted Pair (Category 2) cable.

Which of these would be suitable for transmission of BIG BANK data both within a local branch and nation-wide?
Give three reasons why you chose this medium. (6 lines) (2 marks)

Fibre Optic cable 0.5 mark
0.5 mark for each reason

Greater capacity for carrying data due to its large bandwidth
Faster data transmission
Less attenuation of signal
Greater repeater spacing

etc.

	*UTP*	*Optical fibre*
*Bandwidth*	Small	Large
*Security*	(1)	(2)
*Cost per metre*	Small	Large
*Cost per Megabyte*	Large	Small
*Susceptibility to electromagnetic interference*	(3)	(4)
*Distance between repeaters*	100 m	50 km

abc AND xyz	…returns documents which contain the character strings "abc" and "xyz" in the same paragraph.
abc OR xyz	…returns the documents which contain either character strings "abc" or "xyz" or both in the same paragraph.
"abc xyz pqr"	Use of the quotation marks returns documents which contain the exact phrase "abc xyz pqr".
abc CLOSE(10) xyz	…returns documents which contain the character strings "abc" and "xyz" in the same paragraph as long as the strings are close by. In this example, within 10 words.
abc AND (xyz OR pqr)	Use of the parentheses allows for the logical grouping of commands. In this case the documents would either contain the character strings "abc" and "xyz", or the strings "abc" and "pqr".
abc NOT xyz	…returns documents that contain the character string "abc" but do not contain the string "xyz".
Note: All the search engine command words (AND, OR, CLOSE and NOT) must be entered in uppercase. Apart from the command words, the search engine is not case sensitive.