# Recent questions tagged sliding-window

1
Consider the sliding window flow-control protocol operating between a sender and a receiver over a full-duplex error-free link. Assume the following: The time taken for processing the data frame by the receiver is negligible. The time taken for processing the ... of the number of frames, (rounded to the nearest integer) needed to achieve a link utilization of $50\%$ is_____________.
2
When we use slow-start algorithm, the size of the congestion window increases _______ until it reaches a threshold. Additively Multiplicatively Exponentially None of the options
3
Station $A$ uses $32$ byte packets t transmit messages to station $B$ using sliding window protocol. The round trip delay between $A$ and $B$ is $40$ milliseconds and the bottleneck bandwidth on the path between $A$ and $B$ is $64$ kbps. The optimal window size of $A$ is $20$ $10$ $30$ $40$
4
In go back n arq, the reciever window size is 1 and the sender window size is let's suppose 3.Now if the sender sends the frames with sequence numbers in order 0,1,2 and the reciever sends cumulative acknowledgement with number 3 and now expects a frame number ... order and sender must keep on time out and sending the frames again.plz explain how will this be resolved or am I missing something?
1 vote
5
Compute the fraction of the bandwidth that is wasted on overhead (headers and retransmissions) for protocol selective repeat on a heavily loaded 50-kbps satellite channel with data frames consisting of 40 header and 3960 data bits. Assume that the signal propagation time from the ... error rate for data frames is 1%, and the error rate for NAK frames is negligible. The sequence numbers are 8 bits.
6
Frames of 1000 bits are sent over a 1-Mbps channel using a geostationary satellite whose propagation time from the earth is 270 msec. Acknowledgements are always piggybacked onto data frames. The headers are very short. Three-bit sequence numbers are used. What is the maximum achievable channel utilization for (a) Stop-and-wait? (b) go back n? (c) selective repeat?
1 vote
7
Consider the operation of protocol 6 ( Selective repeat Protocol) over a 1-Mbps perfect (i.e., error-free) line. The maximum frame size is 1000 bits. New packets are generated 1 second apart. The timeout interval is 10 msec. If the special acknowledgement timer were eliminated, unnecessary timeouts would occur. How many times would the average message be transmitted?
1 vote
8
(a) The distance from earth to a distant planet is approximately 9 1010 m. What is the channel utilization if a stop-and-wait protocol is used for frame transmission on a 64 Mbps point-to-point link? Assume that the frame size is 32 KB and the speed ... . For what send window size will the link utilization be 100%? You may ignore the protocol processing times at the sender and the receiver.
1 vote
9
Imagine a sliding window protocol using so many bits for sequence numbers that wraparound never occurs. What relations must hold among the four window edges and the window size, which is constant and the same for both the sender and the receiver?
1 vote
10
A Go-Back-5 ARQ scheme is employed on a 200 meters cable between two nodes A and B to send frames of size 10,000 bits with bit rate 1 Mbps and bit error probability of 10$^{-5}$. Headers and acknowledgements are 20 bytes each. The Speed of propagation of ... parameter (except for the cable length), what is the maximum distance between the two nodes for which S&W will be as efficient as a GBN.
1 vote
11
A 1 Mbps satellite link connects two ground stations. The altitude of the satellite is 6000 km and speed of the signal is 3 10^8 m/s. What should be the packet size for a channel utilization of 50% for a satellite link using go-back-63 ... that the acknowledgment packets are negligible in size and that there are no errors during communication. 81031 Bytes 83101 Bytes 801301 Bytes 81301 Bytes
12
Consider two computers A and B are connected through a network of 30 Mbps. Assume the distance between them is 3000km and the signal propagation speed is same as the speed of light and the packet size is 12 KB. What is the minimum number of bits required for window to achieve 100% of utilization during GoBack-N and selective repeat protocol? A . 5 and 6 B. 6 and 7 C. 6 and 6 D. 7 and 8
1 vote
13
Q.Consider a network connecting two systems connected 2000 Km apart. The band width of the network is 70 Mbps. The propagation speed of the signal is 2 10 m/sec and average size of the frame is 10 KB. Assume processing delays at nodes are negligible. Selective repeat sliding window ... KB as 10 x 10^3 bits , how? it should be multiplied with 8 to convert frame to bits. correct me if i m wrong.
14
There are two stations A and B connected by a $512 * 10^3$ bps network using a sliding window protocol. The speed of the signal is $10^8$ meter/sec and the distance between two stations is $45,000$ km. If the packet size is $256$ B, then what will be the optimal window size(in packets)?
1 vote
15
Frames of 20000 bytes are sent over 10 MBps full duplex link between 2 hosts. Propagation is 45 ms.Suppose that the sliding window protocol is used with the sender window size of 16 and acknowledgements are piggybacked.After sending 35 frames , what is the minimum time sender will have to wait before starting transmission of the next frame
1 vote
16
I was going through this question; The link A-R is instantaneous , but the R->B link transmits only 1 packet each second , one at a time . Assume A sends to B using sliding window protocol with window size =4 , For time t=2 , state what packets arrive ... zero is not yet acknowledged. Is this wrong? Or I am wrong and sliding window protocol means Selective Repeat and it sends ACK for each frame?
1 vote
17
Consider an error-free 64kbps satellite channel used to send 512 bytes data frames in one direction, with very short acknowledgements coming back the other way. assume the earth-satellite propagation time is 270 msec. What is the minimum window size so that the channel is fully utilized? I am getting answer as 7. Answer given 10.
1 vote
18
Consider two stations communicates via 1 Mbps satellite link with propagation delay of 270 msec. The satellite serves merely to retransmit data received from one station to another, with negligible switch delay. If Ethernet frame size is 1024 bits with 3 bits sequence number, then the maximum possible data throughput is ___(upto 2 decimal places).
1 vote
19
I am unable to understand their explanation,can anyone explain it in a better way?
1 vote
20
Assume 2 computers are connected via a network, The networks use GoBack7 SW protocol for maintaining flow control. It is observed that every $5^{th}$ packet that has been sent through the network is lost. The number of extra packets needs to resend for transmitting 10 such packet through the network is______________________.
21
22
Suppose you are designing a sliding window protocol for a $1Mbps$ point to point link which has one way latency of $1.25s$. Assuming that each frame carries $1kB$ of data, determine the minimum number of bits required for the sequence number. Answer provided - $9$ bits.
23
consider a network connecting two nodes A and B having a propagation delay of 6*10^-4 micro sec.bandwidth of network is 150 Mbps if each frame size is 5000 bytes and both uses go back n sliding window protocal, where maximum 100 frames can be sent at a time then the maximum possible data rate is ----- [ mbps]