Suppose nodes A and B are on the same 10 Mbps broadcast channel, and the propagation delay between the two nodes is 245 bit times. Suppose A and B send Ethernet frames at the same time, the frames collide, and then A and B choose different values of K in the CSMA/CD algorithm. Assuming no other nodes are active, can the retransmissions from A and B collide? For our purposes, it suffices to work out the following example. Suppose A and B begin transmission at t=0 bit times. They both detect collisions at t=245 t bit times. Suppose KA=0 and KB=1. At what time does B schedule its retransmission? At what time does A begin transmission? (Note: The nodes must wait for an idle channel after returning to Step 2-see protocol.) At what time does A's signal reach B? Does B refrain from transmitting at its scheduled time2

Suppose nodes A and B are on the same 10 Mbps broadcast channel, and the propagation delay between the two nodes is 245 bit times. Suppose A and B send Ethernet frames at the same time, the frames collide, and then A and B choose different values of K in the CSMA/CD algorithm. Assuming no other nodes are active, can the retransmissions from A and B collide? For our purposes, it suffices to work out the following example. Suppose A and B begin transmission at t=0 bit times. They both detect collisions at t=245 t bit times. Suppose KA=0 and KB=1. At what time does B schedule its retransmission? At what time does A begin transmission? (Note: The nodes must wait for an idle channel after returning to Step 2-see protocol.) At what time does A's signal reach B? Does B refrain from transmitting at its scheduled time2

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

See similar textbooks

Similar questions

Suppose nodes A and B are on the same 10 Mbps broadcast channel, and the propagation delay between the two nodes is 245 bit times. Suppose A and B send Ethernet frames at the same time, the frames collide, and then A and B choose different values of K in the CSMA/CD algorithm. Assuming no other nodes are active, can the retransmissions from A and B collide? For our purposes, it suffices to work out the following example. Suppose A and B begin transmission at t=0 bit times. They both detect collisions at t=245 t bit times. Suppose KA=0 and KB=1. At what time does B schedule its retransmission? At what time does A begin transmission? (Note: The nodes must wait for an idle channel after returning to Step 2-see protocol.) At what time does A's signal reach B? Does B refrain from transmitting at its scheduled time?
Consider sending real-time data from Host A to Host B over a packet-switched network. Host A takes an 8-bit measurement every millisecond, and Host A collects these into 64-byte packets. There is one link between Hosts A and B; its transmission rate is 5 Mbps, its propagation delay is 2 × 108 meters/sec, and its length is 3 km. As soon as Host A gathers a packet, it sends the packet to Host B. How much time elapses from the time that Host A begins to take the first measurement in a packet until the entire packet reaches Host B?
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 1,500 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?
Let the two host X and Y connected via a packet switch with 107 bits per second links. Switch is placed at 50 km from X. X and Y are located at 100 Kilometer apart also the propagation speed along the link is 2 × 108 m/s. The switch begins forwarding a packet after 0.1 milliseconds it receives the packet. If 1000 bytes of File are needed to be transmitted and each packet size is 500 bytes, the time elapsed between the transmission of the first bit of data and the reception of the last bit of the data in millisecond is
Nodes A and B are on the same 10 Mbps Ethernet segment, and the propagation delay between two nodes is 225 bit times. Suppose A and B send frames at t = 0 , the frames collide then at what time they (A or B) finish transmitting a jam signal. Assume a 48 bit jam signal
Consider the scenario below where 4 TCP senders are connected to 4 receivers. The servers transmit to the receiving hosts at the fastest rate possible (i.e., at the rate at which the bottleneck link between a server and its destination is operating at 100% utilization, and is fairly shared among the connections passing through that link). R =1 Gbps and Rc is 300 Mbps and Rs is 400 Mbps. And that all four senders have data to send, What is the minimum value of Re that will ensure that the connections to Host-1 and Host-2 are not bottlenecked at links with capacity Rc or Re?
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.
Suppose that there are three inter-media nodes between Host 1 and Host 2, and the transmission rate of each link is 4.096 Mbps. The time of end-to-end circuit established is 0.5 second. How much seconds does it take to send a file of 8.192M byte from host H1 to host H2 over a packet-switched network?
Suppose a new CSMA/CD protocol is designed for a 100 Mbps bus network with topology similar to 10Base2. The minimum frame length is 40 bytes. What is the maximum length of the longest cable connecting two nodes so that the collision detection mechanism still works? Write symbolic equations (e.g. using d=distance, R=data rate, etc.) and derive the solution. Explain with words what is going on.
In cdma2000 reverse link, a user stream of 9.6kbps is sent to an encoder r = 14 (4 coded bit for every 1 information bit), K = 9. and then through a symbol repetition (2x) (repeats the encoded bits twice). What coded data rate after repetition is obtained? What Walsh code length should you use to spread that stream into a typical 1.2288Mcps CDMA channel?
Consider a broadcast channel with N nodes and a transmission rate of R bps. Suppose the broadcast channel uses polling (with an additional polling node) for multiple access. Suppose the amount of time from when a node completes transmission until the subsequent node is permitted to transmit (that is, the polling delay) is dpoll. Suppose that within a polling round, a given node is allowed to transmit at most Q bits. What is the maximum throughput of the broadcast channel?
Frames of 1000 bits are sent over a 106 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). 1.1 What is the minimum number of bits (1) that will be required to represent the sequence numbers distinctly? Assume that no time gap needs to be given between transmission of two frames.