计算机网络代写｜COMP90007 Internet Technologies Practice Exam

本次是一个澳洲的计算机代写网络的限时测试

Question 1 [4 marks]

Briefly explain key advantages and disadvantages of using Fibre Optics versus Copper Wire.

Question 2 [4 marks]

(1) How can you increase the bit rate of a 1200KHz line from X bit/s to 3X bit/s without
changing the frequency?

(2) Consider a telephone line that is bandwidth limited to 4kHz. If we use 32 levels, what is
the bit rate achieved to transmit data?

Question 3 [2 marks]

(1) The following data fragment occurs in the middle of a data stream for which the byte
stuffing algorithm described in the lectures is to be applied:
A B ESC D FLAG FLAG ESC C

Show the output data stream after the byte-stuffing algorithm has been applied.

(2) What is the maximum overhead in the byte-stuffing algorithm in general and when does
it occur?

Question 4 [2 marks]

Briefly explain the difference in operation and philosophy of two approaches to error
handling on the data link layer, error-correcting and error-detecting.

Question 5 [2 marks]

If a LAN is under high load, would it be more efficient to use a contention protocol or a
collision free protocol in the MAC sublayer? Briefly explain your answer.

Question 6 [3 marks]

Give the name of one sliding window protocols and briefly explain how that protocol works
at Data Link Layer when a transmission error occurs.

Question 7 [4 marks]

A router has built the following routing table. The router can directly deliver packets over
Interface 0 and Interface 1 or it can forward to routers R2, R3 and R4.

Describe what the router does if a packet addressed to each of the following destinations is
received.

(1) 148.96.40.12
(2) 196.4.153.50