Prescription:DC300 Data Communications

Aim of Module	Students will gain an understanding of techniques used to compress data and to ensure network data integrity and security, and will extend their knowledge of data network protocols.
Credits	7
Knowledge Assumed From	DC200 Data Communications
Suggested Time	70 student learning hours
Prescription Expiry Date	Nov 2002

Level and Assessment Schedule
Topics	Highest Skill Level	Suggested Assessment Percentage
1 Network Integrity and Security	P	45
2 Data Network Protocols	A	55
		100

LEARNING OUTCOMES The Student Will
P	1	Explain how the integrity and security of data transmissions and the associated networks is ensured, how data is compressed and investigate the use of these techniques in a practical application.
A	2	Describe typical public data network protocols and use a protocol analyser to examine in detail the data link and network layers.
	Access to synchronous data communications equipment and a protocol analyser is essential.

CONTENT

1  Network Integrity and Security

>	An explanation of data integrity will include;
	a)	Causes of errors on transmission media:
	-	attenuation and distortion
	-	methods of improving line quality
	b)	Error detection/correction:
	-	error detection methods including parity, block sum check (BCC) and cyclic redundancy check (CRC)
	-	error correction methods including Forward Error Control (FEC);
		(eg. Hamming, and backward error control, including echo and Automatic Repeat Request (ARQ))
>	An explanation of security will include:
	-	data encryption methods; e.g. Data Encryption Standard (DES)
		- multi-user system dial-back
		- security e.g. 128 bit
>	Data compression methods will include Huffman coding and current modem techniques; eg. V.42bis and MNP.
>	Investigation of these techniques will require monitoring network activity, identification of potential problems, including complete loss of the network, and documenting procedures for recovering a networked system.

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2  Data Network Protocols

>	Typical public data network protocols will include the following higher level data link control (HDLC) methods; LAPB and LAPD associated with X.25 (PSN), Frame Relay systems and ISDN.
>	Data link control protocol details will include; frame formats, transparency, error handling and retransmissions, implementation details and frame analysis.
>	Network layer protocol details will include; packet formats, routing methods, implementation details and packet analysis.
>	Investigation of the layered architecture of ATM, will include the lower layers unique to this high-speed transport technology.

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