COMPUTER NETWORKS QUESTION : In TCP, hosts need to set the retransmission timeout (RTO) dynamically to adapt for the routing performance and optimize the bandwidth utilization. Assume that one sending hosts found from previous packet/acknowledgement pairs that the RTT between it and the receiver is 45 mS. What will be the RTO of that sending host after receiving a new packet/Ack pair with a new RTT sample = 100 mS. (assume that ?=0.875)

COMPUTER NETWORKS QUESTION : In TCP, hosts need to set the retransmission timeout (RTO) dynamically to adapt for the routing performance and optimize the bandwidth utilization. Assume that one sending hosts found from previous packet/acknowledgement pairs that the RTT between it and the receiver is 45 mS. What will be the RTO of that sending host after receiving a new packet/Ack pair with a new RTT sample = 100 mS. (assume that ?=0.875)

Operations Research : Applications and Algorithms

4th Edition

ISBN:9780534380588

Author:Wayne L. Winston

Publisher:Wayne L. Winston

Chapter20: Queuing Theory

Section20.10: Exponential Queues In Series And Open Queuing Networks

Problem 8P

See similar textbooks

Similar questions

TCP congestion control example. Consider the figure below, where a TCP sender sends 8 TCP segments at t = 1, 2, 3, 4, 5, 6, 7, 8. Suppose the initial value of the sequence number is 0 and every segment sent to the receiver each contains 100 bytes. The delay between the sender and receiver is 5 time units, and so the first segment arrives at the receiver at t = 6. The ACKs sent by the receiver at t = 6, 7, 8, 10, 11, 12 are shown. The TCP segments (if any) sent by the sender at t = 11, 13, 15, 16, 17, 18 are not shown. The segment sent at t=4 is lost, as is the ACK segment sent at t=7. TCP sender t=1 T t=2 t=3 t=4+ t=5- t=6+ t=11 t=12 t=13 t=14 t=15 t=16 t=17 t=18 I data segment data segment data segment data segment data segment data segment data segment data segment ACK ACK ACK ACK ACK ACK Ty A A V V htt TCP receiver t=6 t=7 t=8 t=9 t=10 t=11 t=12 t=13 What does the sender do at t=17? You can assume for this question that no timeouts have occurred.
TCP congestion control example. Consider the figure below, where a TCP sender sends 8 TCP segments at t = 1, 2, 3, 4, 5, 6, 7, 8. Suppose the initial value of the sequence number is 0 and every segment sent to the receiver each contains 100 bytes. The delay between the sender and receiver is 5 time units, and so the first segment arrives at the receiver at t = 6. The ACKS sent by the receiver at t = 6, 7, 8, 10, 11, 12 are shown. The TCP segments (if any) sent by the sender att = 11, 13, 15, 16, 17, 18 are not shown. The segment sent at t=4 is lost, as is the ACK segment sent at t=7. t=1 T data segment t=2+ data segment data segment-- t=3 TCP sender TCP receiver t=4+ t=5+ data segment - data segment t=6+ t36 data segment t=7 data segment t=8 data segment t=9 ACK + t=10 k -- ACK t=11 t=11 t=12 t=12 t=13 t=13 t=14 ACK -ACK ACK t=15 t=16 t=17 ACK t=18 What does the sender do at t=17? You can assume for this question that no timeouts have occurred.
Consider four Internet hosts, each with a TCP session. These four TCP sessions share a common bottleneck link - all packet loss on the end-to-end paths for these four sessions occurs at just this one link. The bottleneck link has a transmission rate of R. The round trip times, RTT, for all fours hosts to their destinations are approximately the same. No other sessions are currently using this link. The four sessions have been running for a long time. i) What is the approximate throughput of each of these four TCP sessions? Explain your answer briefly. ii) What is the approximate size of the TCP window at each of these hosts? Explain briefly how you arrived at this answer.
TCP a. Consider two TCP connections, one between Hosts A (sender) and B (receiver), and another between Hosts C (sender) and D (receiver). The RTT between A and B is half that of the RTT between C and D. Suppose that the senders' (A's and C's) congestion window sizes are identical. Is their throughput (number of segments transmitted per second) the same? Explain. b. Now suppose that the average RTT between A and B, and C and D are identical. The RTT between A and B is constant (never varies), but the RTT between C and D varies considerably. Will the TCP timer values of the two connections differ, and if so, how are they different, and why are they different? Give one reason why TCP uses a three-way (SYN, SYNACK, ACK) handshake rather than a two-way handshake to initiate a connection. a.
A packet switch receives a packet and determines the outbound link to which the packet should be forwarded. When the packet arrives, one other packet is halfway done being transmitted on this outbound link and four other packets are waiting to be transmitted. Packets are transmitted in order of arrival. Suppose all packets are 1,200 bytes and the link rate is 2 Mbps. What is the queuing delay for the packet? More generally, what is the queuing delay when all packets have length L, the transmission rate is R, x bits of the currently-being-transmitted packet have been transmitted, and n packets are already in the queue?
A sender with window size (W=3) is connected to a selective repeat receiver by a link with bandwidth =106 bytes/second and propagation delay of 0.25 msec. The receiver sends Positive ACK for correctly received packets. For each packet sent, the sender sets a timer with time out value of 5 msec. On receiving an ack for a packet, the timer for that packet is cancelled. If the timer expires, that packet is retransmitted immediately. Assume that the sender sends packets 1, 2, and 3 (at t=0, packet size =1000 Bytes) and packet 2 is lost. NO other packet is lost. Under this scheme , at what time in msec would all the packets been received at the receiver.
Consider a TCP connection betweek two hosts between A and B. The first data byte sent by A is numbered 1. The LastByteRcvd at B is 500. Then, the range of values SendBase at A may take is from to 500
An HTTP client opens a TCP connection using an initial sequence number (ISN) of 14,534 and the ephemeral port number of 59,100. The server opens the connection with an ISN of 21,732. Show the three TCP segments during the connection establishment if the client defines the rwnd of 4000 and the server defines the rwnd of 5000. Ignore the calculation of the checksum field.
In TCP connection, congestion occurs if the load on the network is greater than the capacity of the network. TCP uses the following algorithm to handle congestion. The algorithm is based on the size of the congestion window (cwnd) which starts with one maximum segment size (MSS). The MSS is determined during connection establishment. At each time the whole window of segments is acknowledged (one transmission), the size of the window grows exponentially. To stop this exponential growth, the sender keeps the track of a threshold. The threshold is set to 16 MSS. After reaching the threshold, the size of the congestion window is increased by 1. After how many transmissions the congestion window size will be 22 MSS?
Consider a TCP connection with congestion window size 40 KB, maximum segment size is 2 KB, if time taken by TCP connection to get 37 KB congestion window is 351 ms, round trip time of the connection is __(ms).
Multi-hop network: Given two hosts A and B, and one router between them. Packet size is L bits and the link bandwidth is R bps for both links.Suppose A has two packet to send to B.How long does it take starting from A sending the first bit of first packettill B receives the last bit of the last packet?
Given a M/M/1 queue, which has packets arriving at a rate 2 packets/sec, an output link rate R bps, and an average packet size of 1500 bytes, write down: the expression for T, the average delay for a packet (i.e., from arrival till completing transmission at the output). b. the expression for the output utilization c. the expression for average number of packets in the queue d. the expression for average number of packets in the output NIC