search
Log In

Recent questions tagged transport-layer

0 votes
2 answers
2
Suppose two TCP connections are present over some bottleneck link of rate R bps. Both connections have a huge file to send (in the same direction over the bottleneck link). The transmissions of the files start at the same time. What transmission rate would TCP like to give to each of the connections?
asked Apr 18, 2019 in Computer Networks ajaysoni1924 206 views
0 votes
1 answer
3
Suppose Host A sends two TCP segments back to back to Host B over a TCP connection. The first segment has sequence number 90; the second has sequence number 110. How much data is in the first segment? Suppose that the first segment is lost but the second segment arrives at B. In the acknowledgment that Host B sends to Host A, what will be the acknowledgment number?
asked Apr 18, 2019 in Computer Networks ajaysoni1924 624 views
0 votes
1 answer
4
True or false? Host A is sending Host B a large file over a TCP connection. Assume Host B has no data to send Host A. Host B will not send acknowledgments to Host A because Host B cannot piggyback the acknowledgments on data. The size of the TCP rwnd never ... sequence number 38 and 4 bytes of data over a TCP connection to Host B. In this same segment the acknowledgment number is necessarily 42.
asked Apr 18, 2019 in Computer Networks ajaysoni1924 161 views
0 votes
0 answers
5
Visit the Selective Repeat Java applet at the companion Web site. Have the source send five packets, and then pause the animation before any of the five packets reach the destination. Then kill the first packet and resume the animation. Describe what happens. Repeat ... . Describe again what happens. Finally, try sending six packets. What happens? How selective repeat and go back-n is different?
asked Apr 18, 2019 in Computer Networks ajaysoni1924 51 views
0 votes
1 answer
6
Visit the Go-Back-N Java applet at the companion Web site. Have the source send five packets, and then pause the animation before any of the five packets reach the destination. Then kill the first packet and resume the animation. Describe what happens ... packet reach the destination and kill the first acknowledgment. Describe again what happens. Finally, try sending six packets. What happens?
asked Apr 18, 2019 in Computer Networks ajaysoni1924 111 views
0 votes
0 answers
7
Suppose that the roundtrip delay between the sender and receiver is constant and known to the sender. Would a timer still be necessary for protocol rdt 3.0 as shown in the figure, assuming that packets can be lost? Explain.
asked Apr 18, 2019 in Computer Networks ajaysoni1924 76 views
0 votes
2 answers
10
Suppose that a Web server runs in Host C on port 80. Suppose this Web server uses persistent connections and is currently receiving requests from two different Hosts, A and B. Are all of the requests being sent through the same socket at Host C? If they are being passed through different sockets, do both of the sockets have port 80? Discuss and explain.
asked Apr 18, 2019 in Computer Networks ajaysoni1924 101 views
1 vote
1 answer
11
Suppose a process in Host C has a UDP socket with port number 6789. Suppose both Host A and Host B each send a UDP segment to Host C with destination port number 6789. Will both of these segments be directed to the same socket at Host C? If so, how will the process at Host C know that these two segments originated from two different hosts?
asked Apr 18, 2019 in Computer Networks ajaysoni1924 102 views
0 votes
2 answers
13
Why is it that voice and video traffic is often sent over TCP rather than UDP in today’s Internet? (Hint: The answer we are looking for has nothing to do with TCP’s congestion-control mechanism.)
asked Apr 18, 2019 in Computer Networks ajaysoni1924 80 views
0 votes
1 answer
15
Consider a TCP connection between Host A and Host B. Suppose that the TCP segments traveling from Host A to Host B have source port number x and destination port number y. What are the source and destination port numbers for the segments traveling from Host B to Host A?
asked Apr 18, 2019 in Computer Networks ajaysoni1924 105 views
0 votes
0 answers
16
Consider a planet where everyone belongs to a family of six, every family lives in its own house, each house has a unique address, and each person in a given house has a unique name. Suppose this planet has a mail service that delivers letters from source house ... member. In your protocol, does the mail service ever have to open the envelope and examine the letter in order to provide its service?
asked Apr 18, 2019 in Computer Networks ajaysoni1924 94 views
0 votes
0 answers
17
Suppose the network layer provides the following service. The network layer in the source host accepts a segment of maximum size 1,200 bytes and a destination host address from the transport layer. The network layer then guarantees to deliver the segment to the transport ... destination process. In your protocols, does the transport layer have to do anything in the core of the computer network?
asked Apr 18, 2019 in Computer Networks ajaysoni1924 59 views
0 votes
0 answers
18
Design and implement a chat system that allows multiple groups of users to chat. A chat coordinator resides at a well-known network address, uses UDP for communication with chat clients, sets up chat servers for each chat session, and maintains a chat session directory ... client allows users to start, join, and leave a chat session. Design and implement the coordinator, server, and client code.
asked Mar 18, 2019 in Computer Networks ajaysoni1924 151 views
0 votes
1 answer
19
What is the bandwidth-delay product for a 50-Mbps channel on a geostationary satellite? If the packets are all 1500 bytes (including overhead), how big should the window be in packets?
asked Mar 18, 2019 in Computer Networks ajaysoni1924 166 views
0 votes
1 answer
20
To get around the problem of sequence numbers wrapping around while old packets still exist, one could use 64-bit sequence numbers. However, theoretically, an optical fiber can run at 75 Tbps. What maximum packet lifetime is required to make sure that future 75-Tbps ... not have wraparound problems even with 64-bit sequence numbers? Assume that each byte has its own sequence number, as TCP does.
asked Mar 18, 2019 in Computer Networks ajaysoni1924 76 views
0 votes
0 answers
21
A CPU executes instructions at the rate of 1000 MIPS. Data can be copied 64 bits at a time, with each word copied costing 10 instructions. If an coming packet has to be copied four times, can this system handle a 1-Gbps line? For simplicity, assume that all instructions, even those instructions that read or write memory, run at the full 1000-MIPS rate.
asked Mar 18, 2019 in Computer Networks ajaysoni1924 124 views
0 votes
0 answers
22
Suppose that you are measuring the time to receive a segment. When an interrupt occurs, you read out the system clock in milliseconds. When the segment is fully processed, you read out the clock again. You measure 0 msec 270,000 times and 1 msec 730,000 times. How long does it take to receive a segment?
asked Mar 18, 2019 in Computer Networks ajaysoni1924 58 views
0 votes
1 answer
23
0 votes
0 answers
24
To address the limitations of IP version 4, a major effort had to be undertaken via IETF that resulted in the design of IP version 6 and there are still is significant reluctance in the adoption of this new version. However, no such major effort is needed to address the limitations of TCP. Explain why this is the case.
asked Mar 18, 2019 in Computer Networks ajaysoni1924 86 views
1 vote
1 answer
25
What is the fastest line speed at which a host can blast out 1500-byte TCP payloads with a 120-sec maximum packet lifetime without having the sequence numbers wrap around? Take TCP, IP, and Ethernet overhead into consideration. Assume that Ethernet frames may be sent continuously.
asked Mar 18, 2019 in Computer Networks ajaysoni1924 245 views
0 votes
1 answer
26
A TCP machine is sending full windows of 65,535 bytes over a 1-Gbps channel that has a 10-msec one-way delay. What is the maximum throughput achievable? What is the line efficiency?
asked Mar 18, 2019 in Computer Networks ajaysoni1924 107 views
0 votes
1 answer
27
If the TCP round-trip time, RTT, is currently 30 msec and the following acknowledgements come in after 26, 32, and 24 msec, respectively, what is the new RTT estimate using the Jacobson algorithm? Use α = 0.9.
asked Mar 18, 2019 in Computer Networks ajaysoni1924 153 views
0 votes
1 answer
28
Suppose that the TCP congestion window is set to 18 KB and a timeout occurs. How big will the window be if the next four transmission bursts are all successful? Assume that the maximum segment size is 1 KB.
asked Mar 18, 2019 in Computer Networks ajaysoni1924 172 views
0 votes
1 answer
29
Consider the effect of using slow start on a line with a 10-msec round-trip time and no congestion. The receive window is 24 KB and the maximum segment size is 2 KB. How long does it take before the first full window can be sent?
asked Mar 18, 2019 in Computer Networks ajaysoni1924 131 views
...