Computer Network
Q61.
How many check bits are required for 16 bit data word to detect 2 bit errors and single bit correction using hamming code?Q62.
Consider a token ring network with a length of 2km having 10 stations including a monitoring station. The propagation speed of the signal is 2x10^{8} m/s and the token transmission time is ignored. If each station is allowed to hold the token for 2 \musec, the minimum time for which the monitoring station should wait (in \musec) before assuming that the token is lost is _______.Q63.
A bit-stuffing based framing protocol uses an 8-bit delimiter pattern of 01111110. If the output bit-string after stuffing is 01111100101, then the input bit-string isQ64.
Suppose that the stop-and-wait protocol is used on a link with a bit rate of 64 kilobits per second and 20 milliseconds propagation delay. Assume that the transmission time for the acknowledgement and the processing time at nodes are negligible. Then the minimum frame size in bytes to achieve a link utilization of at least 50% is______________.Q65.
A mechanism or technology used in Ethernet by which two connected devices choose common transmission parameters such as speed, duplex mode and flow control is calledQ66.
Consider the store and forward packet switched network given below. Assume that the bandwidth of each link is 10^{6} bytes / sec. A user on host A sends a file of size 10^{3} bytes to host B through routers R1 and R2 in three different ways. In the first case a single packet containing the complete file is transmitted from A to B. In the second case, the file is split into 10 equal parts, and these packets are transmitted from A to B. In the third case, the file is split into 20 equal parts and these packets are sent from A to B. Each packet contains 100 bytes of header information along with the user data. Consider only transmission time and ignore processing, queuing and propagation delays. Also assume that there are no errors during transmission. Let T1, T2 and T3 be the times taken to transmit the file in the first, second and third case respectively. Which one of the following is CORRECT?Q67.
Consider a LAN with four nodes S_{1},S_{2},S_{3} \; and \; S_{4} . Time is divided into fixed-size slots, and a node can begin its transmission only at the beginning of a slot. A collision is said to have occurred if more than one node transmit in the same slot. The probabilities of generation of a frame in a time slot by S_{1},S_{2},S_{3} \; and \; S_{4} are 0.1, 0.2, 0.3 and 0.4, respectively. The probability of sending a frame in the first slot without any collision by any of these four stations is _____________.Q68.
Consider a selective repeat sliding window protocol that uses a frame size of 1 KB to send data on a 1.5 Mbps link with a one-way latency of 50 msec. To achieve a link utilization of 60%, the minimum number of bits required to represent the sequence number field is ________.Q69.
Consider a CSMA/CD network that transmits data at a rate of 100 Mbps (10^{8} bits per second) over a 1 km (kilometer) cable with no repeaters. If the minimum frame size required for this network is 1250 bytes, what is the signal speed (km/sec) in the cable?Q70.
What will be the efficiency of a Stop and Wait protocol, if the transmission time for a frame is 20ns and the propagation time is 30ns?