PART Ⅰ: ChoiceB 1. Which of the following services does not the transport layer provide for the application layer?A.In-order delivery of data segments between processesB.Best effort delivery of data segments between communicating hostsC.Multiplexing and demultiplexing of transport layer segmentsD.Congestion controlA 2. What are the two of the most important protocols in the Internet?A. TCP and IPB. TCP and UDPC. TCP and SMTPD. ARP and DNSC 3. The Internet provides two services to its distributed applications: a connection oriented reliable service and a ( ).A. connection oriented unreliable serviceB. connectionless reliable serviceC. connectionless unreliable serviceD. In order data transport serviceD 4. Processes on two different end systems communicate with each other by exchanging ( ) across the computer network.A. packetsB. datagramC. framesD. messagesA 5. The job of delivering the data in a transport-layer segment to the correct socket is called ( ).A. demultiplexingB. multiplexingC. TDMD. FDMC 6. Two important reasons that the Internet is organized as a hierarchy of networks for the purposes of routing are:A.Least cost and maximum free circuit availabilityB.Message complexity and speed of convergenceC.Scale and administrative autonomyD.Link cost changes and link failureB 7. Which of characters is not distance-vector algorithm’s characters？（）A. iterativeB. globalC. asynchronousD. distributedD 8. The length of IPV6 address is （）bits.A. 32B. 48C. 64D. 128C 9. The host component of a CIDR address of the form a.b.c.d/25 can contain addresses for:A.225 hosts (minus “special” hosts)B.512 hosts (minus “special” hosts)C.2(32-25) hosts (minus “special” hosts)D.25 hosts (minus “special” hosts)C 10. The primary function of the address resolution protocol (ARP) that resides in Internet hosts androuters is:A.To provide LAN router functionsB.To translate between LAN addresses and physical interface addressesC.To translate IP addresses to LAN addressesD.To calculate the shortest path between two nodes on a LANA 11. The POP3 protocol runs over ____ and uses port ____.A. TCP 110B. UDP 110C. UDP 25D. TCP 25D 12.When a destination host transport layer receives data from the network layer, it unambiguouslyidentifies the appropriate process to pass the data to by using a triplet consisting of:A. Source port #, destination IP address, and source IP addressB. Destination port #, source port #, process ID#C. Destination port #, source port #, destination IP addressD. Destination port #, source port #, source IP addressD 13. From the list below, select the items found in the TCP segment structure that are not found in theUDP segment structure:A. Application Generated DataB. Destination Port #C. Source Port #D. Sequence #A 14. The RIP routing protocol is based on an algorithm that is:A. Based on information received only from link “neighbors”B. A link state algorithmC. An OSPF algorithmD. A centralized routing algorithmB 15. With an exterior routing protocol, which of the following issues generally dominates the routing decisions?A. Geographical distance between AS’sB. PolicyC. Number of AS’s traversedD. Current congestion levels in the AS’sA 1. End system are connected together by ____.A. communication linksB. application layerC. transport layerD. the network layerC 2. Which application’s NOT using TCP?A. SMTPB. HTTPC. DNSD. All of themB 3. In the polling protocols, the master node polls each of the nodes in a/an ____ fashion.A. randomB. appointedC. round-robinD. uncirculatedC 4. The DNS protocol runs over ____ and uses port ____.A. UDP 36B. TCP 36C. UDP 53D. TCP 53A 5. TCP provides a ____ service to its applications to eliminate the possibility of the sender over-flowingthe receiver’s buffer.A. flow-controlB. congestion controlC. reliability controlD. data connectionD 6. We can classify just about any multiple access protocol as belonging to one of three categories: channel partitioning protocols, random access protocols, and ____.A. address resolution protocolsB. Dynamic host configuration protocolsC. link-control protocolsD. taking-turns protocolsB 8. The maximum transfer unit(MTU) in Ethernet frame structure is ()byte .A. 1000B. 1500C. 800D. 2000B 9. The socket of UDP is identified by _____ and _______.A. source IP address and source port numberB. destination IP address and destination port number.C. source IP address and destination port number.D. destination IP address and source IP address.C 10. Which is not plug and play in the following four items?A. DHCPB. HubsC. RoutersD. SwitchesD 11．Which of routers is not default routers ?A. first-hop routerB. source routerC. destination routerD. second-hop routerB 13. ICMP is_____.A. the protocol of Application layerB. the protocol of network layerC. the protocol of transport layerD. not a part of TCP/IP protocolsB 14. As general, we has following channel partitioning protocols except ____.A. TDMB. CSMAC. FDMD.CDMAD 15. ____ is most used for error reporting.A. UDPB. SMTPC. FTPD. ICMPB 16. The header of IPV6 is ____byte.A. 20B. 40C. 60D. 80B 17. In the network layer these service are host-to-host service provided by ____. （B）A. the transport layer to the network layerB. the network layer to the transport layerC. the network layer to the network layerD. the transport layer to the transport layerA 18. If there is not enough memory to buffer an incoming packet , a policy that drop the arriving packet called ____.A. drop-tailB. packet lossC. protocolD. encapsulationC 19. In either case, a ____ receives routing protocol messages, which are used to configure its forwarding table.A. serverB. hostC. routerD. ModemD 20. Which of the following functions does not belong to PPP___.A. framingB. link-control protocolsC. network-control protocolsD. error correctionB 1. Which of the following services does the Internet network layer provide for the Internet transport layer?A.In-order delivery of data segments between processesB.Best effort delivery of data segments between communicating hostsC.Multiplexing and demultiplexing of transport layer segmentsD.Congestion controlD 2. The main task of the Internet’s Domain Name System (DNS) is to:A.Translate port numbers to IP addressesB.Specify the standards for Internet domain namesC.Provide an authority for registering domain namesD.Translate mnemonic（记忆的）names to IP addressesA 10. The FTP protocol runs over ____ and uses port ____.A. TCP 21B. TCP 80C. UDP 20D. TCP 110C 3.RDT3.0’s receiver FSM is same to:a) RDT1.0 b) RDT2.1 c) RDT2.2 d) RDT2.0B 4.The Transmission Control Protocol (TCP) provides which of the following services?a)End-to-end station addressingb)Application multiplexingc)Inter network routingd)Medium access control (MAC)D 6.Given that the requested information is not available at any intermediate databases, a non-iterated DNS query from a requesting host would follow the path:a)Root name server, local name server, authoritative name serverb)Authoritative name server, root name server, host name serverc)Local name server, root name server, local name server, authoritative name servere)Local name server, root name server, authoritative name serverA 8.lect the four essential steps, briefly described, for terminating a TCP connection between a client and a server, assuming that the initiating host is the client:(1)Client sends TCP segment with ACK0 and final sequence number(2)Client sends TCP segment with FIN =1 and goes into FIN_WAIT state(3)Server sends TCP segment to ACK the client’s FIN request and enters CLOSE_WAIT state(4)Server sends TCP segment with FIN=0(5)Server sends TCP segment with FIN=1(6)Client sends TCP segment with to ACK server’s FIN and enters second FIN_WAIT state(7)Client sends TCP segment with FIN=0a) 2，3，5，6 b) 5，1，2，3 c) 1，3，5，7 d) 2，3，4，6B 10.When compensating for link cost changes in the distance vector algorithm, it can generally be said that:a)Increased costs are propagated quickly, i.e., “bad news” travels fastb)Decreased costs are propagated rapidly, i.e., “good news” travels fastc)Decreased costs do not converged)None of the aboveB 14.As an IP datagram travels from its source to its destination:a)the source IP address is changed at each router to identify the sending routerb)the router uses the destination IP address to consult its routing tablec)the router does not use the IP addresses in the datagramd)the destination IP address is changed at each router to reflect the next hopC 15.From the list below, choose the bit pattern which could be a valid generator value for the CRC code (R) 11010:a)1110b)011010c)100101d)10011A 16.Consider sending a 1300 byte IPv4 datagram into a link that has an MTU of 500 bytes:a)Three fragments are created.b)Four fragments are created.c)Three fragments are created with offsets 0, 500 1000d)The last fragment consists of exactly 300 bytes of data from the original datagramC 17.Suppose one IPv6 router wants to send a datagram to another IPv6 router, but the two are connected together via an intervening IPv4 router. If the two routers use tunneling, then:a)The sending IPv6 router creates an IPv4 datagram and puts it in the data field of an IPv6datagram.b)The sending IPv6 router creates one or more IPv6 fragments, none of which is larger than themaximum size of an IPv4 datagram.c)The sending IPv6 router creates an IPv6 datagram and puts it in the data field of an IPv4datagram.d)The sending IPv6 router creates an IPv6 datagram and intervening IPv4 router will reject theIPv6 datagramD 18.Which of the following was an important consideration in the design of IPv6a)fixed length 40-byte header and specified options to decrease processing time at IPv6 nodesb)128-bit addresses to extend the address spacec)different types of service (flows) definedd)all of the aboveD 19.A network bridge table is used to perform the following:a)Mapping MAC addresses to bridge port numbersb)Forwarding frames directly to outbound ports for MAC addresses it handlesc)Filtering (discarding) frames that are not destined for MAC addresses it handlesd)All of the abovePART Ⅱ: True / False (1 points per question – total:20 points)1. The DNS server can update the records. (T)2. The TCP connection is a direct virtual pipe between the client’s socket and the server’s connection socket. （T）3. SMTP protocol connect the sender’s mail server and receiver’s mail server (T)4. Whereas a transport-layer protocol provides logical communication between processes running on different hosts, a network-layer protocol provides logical communication between hosts. (T)5. UDP and TCP also provide integrity checking by including right-detection fields in their headers. (F)6. If the application developer chooses UDP instead of TCP, then the application is not directly talking with IP. ( F )7. When we develop a new application, we must assign the application a port number. ( T )8. Real-tine applications, like Internet phone and video conferencing, react very poorly to TCP’s congestion control. ( T )9. The sender knows that a received ACK or NAK packet was generated in response to its most recently transmitted data packet. (T)10. To simplify terminology, when in an Internet context, we refer to the 4-PDU as a unit. (F)11. DV algorithm is essentially the only routing algorithm used in practice today in the Internet。
