Flow & Error Control PYQ QUIZ GATE CS

Consider a source computer(S) transmitting a file of size 10⁶ bits to a destination computer(D)over a network of two routers (R₁ and R₂) and three links(L₁, L₂, and L₃). L₁connects S to R₁; L₂ connects R₁ to R₂; and L₃ connects R₂ to D.Let each link be of length 100 km. Assume signals travel over each link at a speed of 10⁸ meters per second.Assume that the link bandwidth on each link is 1Mbps. Let the file be broken down into 1000 packets each of size 1000 bits. Find the total sum of transmission and propagation delays in transmitting the file from S to D?

In the Stop-and-Wait ARQ protocol, the sender must wait for an acknowledgment before:

Consider the data of previous question. Suppose that the sliding window protocol is used with the sender window size of 2ⁱ where is the number of bits identified in the previous question and acknowledgments are always piggybacked. After sending 2ⁱ frames, what is the minimum time the sender will have to wait before starting transmission of the next frame? (Identify the closest choice ignoring the frame processing time.)

The message 11001001 is to be transmitted using the CRC polynomial x³ + 1 to protect it from errors. The message that should be transmitted is:

The distance between two stations M and N is L kilometers. All frames are K bits long. The propagation delay per kilometer is t seconds. Let R bits/second be the channel capacity. Assuming that processing delay is negligible, the minimum number of bits for the sequence number field in a frame for maximum utilization, when the sliding window protocolis used, is:

Consider a token ring network with a length of 2 km having 10 stations including a monitoring station. The propagation speed of the signal is 2 × 10⁸ m/s and the token transmission time is ignored. If each station is allowed to hold the token for 2 μsec, the minimum time for which the monitoring station should wait (in μsec)before assuming that the token is lost is _______.

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 ________.

Station A uses 32 byte packets to transmit messages to Station B using a sliding window protocol. The round trip delay between A and B is 80 milliseconds and the bottleneck bandwidth on the path between A and B is 128 kbps. What is the optimal window size that A should use?

How many 8-bit characters can be transmitted per second over a 9600 baud serial communication link using asynchronous mode of transmission with one start bit, eight data bits, two stop bits, and one parity bit ?

A and B are the only two stations on an Ethernet. Each has a steady queue of frames to send. Both A and B attempt to transmit a frame, collide, and A wins the first backoff race. At the end of this successful transmission by A, both A and B attempt to transmit and collide. The probability that A wins the second backoff race is: