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Chapter 3 Transport Layer1. A transport-layer protocol provides for logical communication between _.A Application processesB HostsC RoutersD End systems2. Transport-layer protocols run in _.A ServersBClientsCRoutersDEnd systems3. In transport layer, the send side breaks application messages into _, passes to network layer.b5E2RGbCAPA FramesB SegmentsC Data-grams D bit streams4. Services provided by transport layer include _.p1EanqFDPwA HTTP and FTPB TCP and IPC TCP and UDPD SMTP5. Which of the following services is not provided by TCP? DXDiTa9E3dA Delay guarantees and bandwidth guaranteesB Reliable data transfers and flow controlsC Congestion controlsD In-order data transfers6. These two minimal transport-layer services-_ and _-are the only two services that UDP provides! RTCrpUDGiTA process-to-process data delivery, error checkingB congestion control, reliable data transferC flow control, congestion controlD In-order data transfer, error checking7. Port numbers scope is _ to _. A 0, 1023B 0, 65535C 0, 127D 0,2558. The port numbers ranging from _to _ are called well-known port number and are restricted.5PCzVD7HxAA 0, 1023B 0, 65535C 0, 127D 0,2559. UDP socket identified by two components, they are_.jLBHrnAILgA source IP addresses and source port numbersB source IP addresses and destination IP addressesC destination IP address and destination port numbersxHAQX74J0XD destination port numbers and source port numbers10. TCP socket identified by a (an _. A 1-tupleB 2-tupleC 3-tupleD 4-tuple11. Which of the following applications normally uses UDP services? LDAYtRyKfEA SMTPB Streaming multimediaC FTPD HTTP18. Which of the following about TCP connection is not correct? Zzz6ZB2LtkA It is a broadcast connectionB It is a point-to-point connectionC It is a pipelined connectionD It is a full duplex connection19. The SYN segment is used for_. A TCP connection setupB TCP flow controlC TCP congestion controlD Closing a TCP connection20. The FIN segment is used for_.A TCP connection setupB TCP flow controlC TCP congestion controlD Closing a TCP connection21. How does TCP sender perceive congestion? A Through a timeout eventB Through a receiving duplicate ACK-s eventC Both A and BD Either A or B22. Extending host-to-host delivery to process-to-process delivery is called transport-layer_ and . dvzfvkwMI1A multiplexing and de-multiplexingB storing and forwardingC forwarding and filteringD switching and routing23. UDP is a _ service while TCP is a connection-oriented service. rqyn14ZNXIA ConnectionlessB ReliableC Connection-orientedD In-order24. The UDP header has only four fields, they are_. EmxvxOtOcoA Source port number, destination port number, length and checksumSixE2yXPq5B Source port number, destination port number, source IP and destination IP6ewMyirQFLC source IP, destination IP, source MAC address and destination MAC addresskavU42VRUsD source IP, destination IP, sequence number and ACK sequence numbery6v3ALoS8925. There are two 16-bit integers: 1110 0110 0110 0110, 1101 0101 0101 0101. Their checksum is_. M2ub6vSTnPA 0100010001000011B 1011101110111100C 1111111111111111D 100000000000000026. The maximum amount of data that can be grabbed and placed in a segment is limited by the_.0YujCfmUCwA Maximum segment size (MSSB MTUC ChecksumD Sequence number27. The MSS is typically set by first determining the length of the largest link-layer frame that can be sent by the local sending host-the so-called_.eUts8ZQVRdA Maximum transmission unit (MTUB MSSC ChecksumD Sequence number28. A File size of 500,000bytes, MSS equals 1000bytes. When we want to transmit this file with TCP, the sequence number of the first segment is 0, and the sequence number of the second segment is _. sQsAEJkW5TA 1000B 999C 1001D 50000029. Because TCP only acknowledges bytes up to the first missing byte in the stream, TCP is said to provide_. GMsIasNXkAA Cumulative acknowledgementsB Selective acknowledgementsC 3 duplicate ACKsD positive ACKs30. Provided =0.125, current value of Estimated-RTT is 0.4s, Sample-RTT is 0.8s, then the new value of Estimated-RTT is _s. TIrRGchYzgA 0.45B 0.6C 0.7D 0.831. Provided RcvBuffer=20,LastByteRcvd=20,LastByteRead=15, then RcvWindow=_. 7EqZcWLZNXA 14B 15C 16D 1032. TCP service does not provide_. A Reliable data transfer B Flow controlC Delay guarantee D Congestion control33. There are two states in TCP congestion control, which are _.lzq7IGf02EA slow start and congestion avoidanceB safe start and congestion avoidanceC slow start and congestion abandonD safe start and congestion abandon34. The transport-layer protocol provides logical communication between _, and the network-layer protocol provides logical communication _.zvpgeqJ1hkA hosts, processes B processes, hostsC threads, processes D processes, threads36. If an application developer chooses _ protocol, then the application process is almost directly talking with IP. NrpoJac3v1A HTTPB RIPC CSMA/CDD UDP37. _ maintains connection-state in the end systems. This connection state includes receive and send buffers, congestion-control parameters, and sequence and acknowledgment number parameters. 1nowfTG4KIA UDPB TCPC DNSD HTTP38. The host that initiates the session in the Internet is labeled as _.fjnFLDa5ZoA server B user agentC clientD router39. With TCP there is no _ between sending and receiving transport-layer entities. tfnNhnE6e5A flow controlB handshakingC.congestion controlD VC setup40. The Internets _ service helps prevent the Internet from entering a state of gridlock. HbmVN777sLA datagramB congestion controlC sliding windowD timeout event41. Connection setup at the transport layer involves _. V7l4jRB8HsA server B only the two end systemsC clientD router42. A _layer protocol provides for logical communication between applications. 83lcPA59W9A transportB applicationC networkingD MAC43. In static congestion window, if it satisfies W*S/R RTT + S/R, the Latency is _.mZkklkzaaPA W*S/R ( RTT+ S/R B 2RTT + O/RC 2RTT + O/R + (k-1W* S/R- (RTT + S/R D 2RTT + S/R44. The receive side of transport layer reassembles segments into messages, passes to _layer. AVktR43bpwA ApplicationB NetworkingC PhysicalD MAC45. In the following four options, which one is correct?ORjBnOwcEdA The variations in the SampleRTT are smoothed out in the computation of the EstimatedRTT2MiJTy0dTTB The timeout should be less than the connections RTTgIiSpiue7AC Suppose that the last SampleRTT in a TCP connection is equal to 1 sec. Then the current value of TimeoutInterval will necessarily be1 secuEh0U1YfmhD Suppose that the last SampleRTT in a TCP connection is equal to 1 sec. Then the current value of TimeoutInterval will necessarily be1 secIAg9qLsgBX46. The port number used by HTTP is _. A 80B 25C 110D 5347. The port number used by SMTP is _. A 80B 25C 110D 5348. The port number used by pop3 is _. A 80B 25C 110D 5349. The port number used by DNS is _. A 80B 25C 110D 5350. The port number used by FTP is _. A 20 and 21B 20C 21D 5351. A UDP socket identified by a _ tuple(s.A 2B 4C 1D 352. A TCP socket identified by a _ tuple(s. A 2B 4C 1D 353. A TCP socket does not include_. A Source MAC addressB Source port numberC Destination IP addressD Destination port number54. Which of following about UDP is not correct. A It is a reliable data transfer protocolB It is connectionlessC no handshaking between UDP sender, receiverD it is a best effort service protocol55. DNS uses _ service. A TCPB UDPC Both TCP and UDPD None of above56. Which of following about UDP is correct?A Finer application-level control over what data is sent, and when WwghWvVhPEB No connection establishment (which can add delay, so no delay for establish a connectionasfpsfpi4kC No connection state (so, UDP can typically support many active clientsooeyYZTjj1D Large packet header overhead (16-B57. Streaming media uses a _ service normally. A TCPB UDPC Both TCP and UDPD None of above58. The UDP header has only _ fields. A 2B 4C 1D 359. Which of the following does not included in UDP header. BkeGuInkxIA Source port numberB Destination port numberC ChecksumD Sequence number60. Which of the following is not a pipelining protocol. PgdO0sRlMoA Rdt1.0B Go-Back-NC Selective repeatD TCP61. In the following four descriptions about MSS and MTU, which one is not correct? 3cdXwckm15A The MSS is the maximum amount of application-layer data in the segmenth8c52WOngMB The MSS is the maximum size of the TCP segment including headersv4bdyGiousC The MSS is typically set by MTUD The MTU means the largest link-layer frame62. The job of gathering data chunks, encapsulating each data chunk with header information to create segments and passing the segments to the network is called _.J0bm4qMpJ9A multiplexing B de-multiplexing C forwarding D routing63. In the following four descriptions about the relationship between the transport layer and the network layer, which one is not correct? XVauA9grYPA The transport-layer protocol provides logical communication between hostsbR9C6TJscwB The transport-layer protocol provides logical communication between processespN9LBDdtrdC The services that a transport-layer protocol can provide are often constrained by the service model of the network-layer protocolDJ8T7nHuGTD A computer network may make available multiple transport protocolsQF81D7bvUA64. Suppose the following three 8-bit bytes: 01010101, 01110000, 01001100. Whats the 1s complement of the sum of these 8-bit bytes? 4B7a9QFw9hA 00010001 B 11101101 C 00010010 D 1000100065. The following four descriptions about multiplexing and de-multiplexing, which one is correct? ix6iFA8xoXA A UDP socket is identified by a two-tuples consisting of a source port number and a destination port number.wt6qbkCyDEB If two UDP segment have different source port number, they may be directed to the same destination process.Kp5zH46zRkC If two TCP segments with different source port number, they may be directed to the same destination process.Yl4HdOAA61D If two TCP segments with same destination IP address and destination port number, they must be the same TCP connection.ch4PJx4BlI66. UDP and TCP both have the fields except _.A source port number B destination port numberC checksum D receive window67. If we define N to be the window size, base to be the sequence number of the oldest unacknowledged packet, and next-seq-num to be the smallest unused sequence number, then the interval nextseqnum,base+N-1 corresponds to packet that _.qd3YfhxCzoA can be sent immediately B have already been transmitted and acknowledgedC cannot be usedD have been sent but not yet acknowledged68. Which of the following about TCP is not correct? E836L11DO5A It is a connectionless protocolB Point-to-point protocolC Reliable, in-order byte steam protocolD Pipelined protocol69. Which of the following about TCP is not correct? S42ehLvE3MA It is a connectionless protocolB full duplex data transfer protocolC connection-oriented protocolD flow controlled protocol70. The maximum amount of data that can be grabbed and placed in a segment is limited by the _. 501nNvZFisA Maximum segment size (MSSB MTUC Sequence numberD Check sum71. The MSS is typically set by first determining the length of the largest link-layer frame that can be sent by the local sending host (the so-called_, and then will fit into a single link-layer frame. jW1viftGw9A Maximum segment size (MSSB MTUC Sequence numberD Check sum72. The MSS is the maximum amount of _layer data in the segment, not the maximum size of the TCP segment including headers.xS0DOYWHLPA ApplicationB TransportC NetworkingD Link73. Which of the following field is not used for connection setup and teardown?LOZMkIqI0wA Sequence numberB TSTC SYND FIN 74. _ is the byte stream number of first byte in the segment. ZKZUQsUJedA Sequence numberB ACK numberC Checksum D port number75. _ is the byte sequence numbers of next byte expected from other side. dGY2mcoKtTA Sequence numberB ACK numberC Checksum D port number76. Because TCP only acknowledges bytes up to the first missing byte in the stream, TCP is said to provide _ acknowledgements.rCYbSWRLIAA Cumulative B SelectiveC SingleD Negative77. Fast retransmit means in the case that _ duplicate ACK-s are received, the TCP sender resend segment before timer expires.FyXjoFlMWhA 3B 4C 5D 678. TCP_ means sender wont overflow receivers buffer by transmitting too much, too fast. TuWrUpPObXA Flow controlB Congestion controlC Reliable data transferD Connection-oriented service79. TCP provides flow control by having the sender maintain a variable called the _. 7qWAq9jPqEA Receive windowB Congestion windowC Sliding windowD buffer80. How does TCP sender perceive congestion? A TimeoutB 3 duplicate ACK-sC Both A and BD None of above81. Transport protocols run in _. A Servers B Clients C Routers D End systems82. Which of the following services is not provided by TCP? llVIWTNQFkA Delay guarantees and bandwidth guaranteesB Reliable data transfers and flow controlsC Congestion controlsD In-order data transfers83. Which service does UDP not provide? A multiplexing B de-multiplexingC error-detection B error-correction84. There are three major events related to data transmission and retransmission in the TCP sender, which one is not in it?yhUQsDgRT1A data received from application above B de-multiplexing segmentC timer timeout D ACK receipt85. Which of the following applications normally uses UDP services?MdUZYnKS8IA SMTP B Streaming multimedia C FTP D HTTP86. Which of the following about TCP connection is not correct?09T7t6eTnoA It is a broadcast connectionB It is a point-to-point connectionC It is a pipelined connectionD It is a full duplex connection87. The SYN segment is used for_. A TCP connection setupB TCP flow controlC TCP congestion controlD Closing a TCP connection88. Which service helps prevent the internet from entering a state of gridlock?e5TfZQIUB5A reliable data transfer B flow controlC congestion control D handshaking procedure89. The Internets _is responsible for moving packets from one host to another.s1SovAcVQMA application layer B transport layerC network layer D link layer90. In the following applications, which one is a bandwidth-sensitive application?GXRw1kFW5sA E-mail B web application C real-time audio D file transfer91. In the following applications, which one uses UDP?UTREx49Xj9A E-mail B web application C file transfer D DNS92. In the following four descriptions, which one is correct?8PQN3NDYyPA If one hosts transport layer uses TCP, then its network layer must use virtual-circuit network.mLPVzx7ZNwB Datagram network provides connection serviceC The transport-layer connection service is implemented in the routerAHP35hB02dD The network-layer connection service is implemented in the router as well as in the end system.NDOcB141gT93. _ is a speeding-matching service-matching the rate which the sender is sending against the rate at which the receiving application is reading.1zOk7Ly2vAA congestion control B flow controlC sliding-window control D variable control94. In the following four descriptions about Rcv-Window, which one is correct?fuNsDv23KhA The size of the TCP RcvWindow never changes throughout the duration of the connectiontqMB9ew4YXB The size of the TCP RcvWindow will change with the size of the TCP RcvBufferHmMJFY05dEC The size of the TCP RcvWindow must be less than or equal to the size of the TCP RcvBufferViLRaIt6skD Suppose host A sends a file to host B over a TCP connection, the number of unacknowledged bytes that A sends cannot exceed the size of the size of the RcvWindow.9eK0GsX7H195. There are 6 flag fields. Which one is to indicate that the receiver should pass the data to the upper layer immediately?naK8ccr8VIA PSH B URG C ACK D RST96. Suppose the TCP receiver receives the segment that partially or completely fills in gap in received data, it will _.B6JgIVV9aoA immediately send ACK B immediately send duplicate ACKC wait some time for arrival of another in-order segmentP2IpeFpap5D send single cumulative97. _ imposes constrain on the rate at which a TCP sender can send traffic into the network.3YIxKpScDMA sliding window B congestion window C receive window D variable window98. Flow control and congestion control are same at that they all limit the rate of the sender, but differ in that _.gUHFg9mdSsA flow control limits its rate by the size of RcvWindow, but congestion control by the traffic on the linkuQHOMTQe79B congestion control limits its rate by the size of RcvWindow, but flow control by the traffic on the linkIMGWiDkflPC flow control mainly is accomplished by the sender, but congestion control by the receiver.WHF4OmOgAwD flow control mainly is accomplished by the receiver, but congestion control by the link.aDFdk6hhPd99. This job of delivering the data in a transport-layer segment to the correct socket is called _.ozElQQLi4TA multiplexing B de-multiplexing C forwarding D routing100. If we define N to be the window size, base to be the sequence number of the oldest unacknowledged packet, and next-seq-num to be the smallest unused sequence number, then the interval base, nextseqnum-1 corresponds to packet that _.CvDtmAfjiAA can be sent immediatelyB have already been transmitted and acknowledgedC cannot be used D have been sent but not yet acknowledged101. _ are the two types of transport services that the Internet provides to the applications.QrDCRkJkxhA TCP and UDP B connection-oriented and connectionless serviceC TCP and IP D reliable data transfer and flow control102. In the following descriptions about persistent connection, which one is not correct?4nCKn3dlMXA The server leaves the TCP connection open after sending a responseijCSTNGm0EB Each TCP connection is closed after the server sending one objectvfB1pxanfkC There are two versions of persistent connection: without pipelining and with pipeliningJbA9VhEou1D The default mode of HTTP uses persistent connection with pipeliningX7Ahr18pJI103. The field of Length in UDP segment specifies the length of _.b3zqXLCqXoA the UDP segment, not including the headerB the UDP segment, including the headerC the UDP segments headerD the Length fiel
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