Computer Network
Q42.
An Ethernet frame that is less than the IEEE 802.3 minimum length of 64 octets is calledQ43.
Consider a binary code that consists of only four valid code words as given below: 00000,01011,10101,11110 Let the minimum Hamming distance of the code be p and the maximum number of erroneous bits that can be corrected by the code be q. Then the values of p and q areQ44.
The values of parameters for the Stop-and-Wait ARQ protocol are as given below: Bit rate of the transmission channel = 1Mbps Propagation delay from sender to receiver = 0.75 ms Time to process a frame = 0.25ms Number of bytes in the information frame =1980 Number of bytes in the acknowledge frame = 20 Number of overhead bytes in the information frame = 20 Assume that there are no transmission errors. Then the transmission efficiency ( expressed in percentage) of the Stop-and - Wait ARQ protocol for the above parameters is _________( correct to 2 decimal places)Q45.
Frames of 1000 bits are sent over a 10^6 bps duplex link between two hosts. The propagation time is 25 ms. Frames are to be transmitted into this link to maximally pack them in transit (within the link). What is the minimum number of bits (I) that will be required to represent the sequence numbers distinctly? Assume that no time gap needs to be given between transmission of two frames.Q46.
A computer network uses polynomials over GF(2) for error checking with 8 bits as information bits and uses x^{3}+x+1 as the generator polynomial to generate the check bits. In this network, the message 01011011 is transmitted asQ47.
________ can detect burst error of length less than or equal to degree of the polynomial and detects burst errors that affect odd number of bits.Q48.
In a token ring network the transmission speed is 10^7 bps and the propagation speed is 200 meters/\mu s. The 1-bit delay in this network is equivalent to:Q49.
Consider a 128 \times 10^{3} bits/second satellite communication link with one way propagation delay of 150 milliseconds. Selective retransmission(repeat) protocol is used on this link to send data with a frame size of 1 kilobyte. Neglect the transmission time of acknowledgement. The minimum number of bits required for the sequence number field to achieve 100% utilization is ________.Q50.
Consider two hosts X and Y, connected by a single direct link of rate 10^{6} bits/sec . The distance between the two hosts is 10,000 km and the propagation speed along the link is 2x10^{8} m/sec . Host X sends a file of 50,000 bytes as one large message to host Y continuously. Let the transmission and propagation delays be p milliseconds and q milliseconds, respectively . Then the values of p and q are