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In data communication, the communication channel is the route along which data is transmitted. The transmission of data can be described by the following four...

In data communication, the communication channel is the route along which data is transmitted. The transmission of data can be described by the following four characteristics:
A. Direction of flow of data.
B. Communication lines.
C. Speed of data transmission.
D. Mode of data transmission.
Required: For each of the following data communication concepts/devices, indicate under which ONE of the above listed characteristics A-D they would best fall: ii. Protocol; iii. Half duplex; iv. Fibre optics; v. Simplex; vi. Analog signal; vii. Micro wave; viii. Band width; ix. Start/stop bit; x. Voice bad.
Explain the term internetworking within the context of data communication. How does a call-back unit and data-encryption equipment enhance security in a computer network?

Answers

Gregory
a) (i) Protocol - D
(ii) Half duplex – A
(iii) Fibre optics – B
(iv) Simplex – A
(v) Analog signal – D
(vi) Microwave – B
(vii) Bandwidth – C
(viii) Start/Stop bit – D
(ix) Asynchronous – D
(x) Voice Band -B

b) Internetworking
This refers to the linking of separate networks, each of which retains its own identity, into an inter-connected network. An interconnected network may consist of an organizational network linked to other organizational networks, to the Internet, to the networks of public telecommunication service providers or to other public networks via a backbone.
c) Call-back unit
When a terminal requests for access to another terminal and authenticates itself, the call-back mechanism interrupts the telecommunications dial-up connection to the other terminal by dialing back the caller (requesting terminal) to validate the terminal?s identity. Call-back units thus prevent terminals from masquerading i.e. falsifying their identities so as to gain additional privileges or access to otherwise forbidden data or systems.
Data Encryption Equipment
These enable data encryption i.e. the process of converting data (plain text) into a secure coded form (cipher text) that cannot be understood without converting back via decryption (the reverse process) to plain text again. Messages can thus be encrypted before they are sent to prevent eavesdropping on messages in transit in a network. Data encryption could also be used to protect data stored on servers from disclosure to intruders (unauthorized users) who have already gained access to the server.
Gregorymasila1 answered the question on March 28, 2018 at 13:13

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