TCP functions at the Open Systems Interconnection(OSI)transport layer, or Layer 4. Its chief responsibility is to ensure reliable end-to-end connectivity. IP, located one layer （1）, at the OSI network layer, or Layer 3,communicates the addresses of each packet’s sender and receiver to the routers along the way .Routers and Layer 3 switches can read IP and other Layer 3 protocols. This information, combined with routing tables and other network intelligence, it takes to get across the room or around the world（2）TCP/IP.The routing process begins with an IP address that is（3）to the sending end station. End stations may be assigned permanent IP addresses or they may borrow them as needed from a Dynamic Host Configuration Protocol(DHCP)server or other service. If the sending end station determines that the destination address is not local, the packet goes to a first-hop router, typically one that is close and has been reassigned to the（4）. The router inspects the packet’s IP address and performs a route table lookup to see if the destination end station resides on the local(physically connected)network, typically called an IP subnet. An IP subnet usually is assigned to each of the router’s network interfaces. If the destination IP address is local, the router searches an internal store of IP addresses and local-device media access control(MAC)addresses. This store is known as the Address Resolution Protocol(ARP) cache. ARP is the universal tool for（5）IP addresses to MAC addresses. If the destination’s MAC address appears, the router installs that MAC address in the packet header(removing its own MAC address because that’s no longer needed)and sends the packet to the destination end station.（1）A. upB. downC. sidewardD. back-fence（2）A. viaB. throughC. byD. through out（3）A. specialB. especialC. uniqueD. particular（4）A. accepterB. senderC. routerD. server（5）A. searchingB. lookingC. locatingD. matching

TCP functions at the Open Systems Interconnection(OSI)transport layer, or Layer 4. Its chief responsibility is to ensure reliable end-to-end connectivity. IP, located one layer （1）, at the OSI network layer, or Layer 3,communicates the addresses of each packet’s sender and receiver to the routers along the way .Routers and Layer 3 switches can read IP and other Layer 3 protocols. This information, combined with routing tables and other network intelligence, it takes to get across the room or around the world（2）TCP/IP.

The routing process begins with an IP address that is（3）to the sending end station. End stations may be assigned permanent IP addresses or they may borrow them as needed from a Dynamic Host Configuration Protocol(DHCP)server or other service. If the sending end station determines that the destination address is not local, the packet goes to a first-hop router, typically one that is close and has been reassigned to the（4）. The router inspects the packet’s IP address and performs a route table lookup to see if the destination end station resides on the local(physically connected)network, typically called an IP subnet. An IP subnet usually is assigned to each of the router’s network interfaces. If the destination IP address is local, the router searches an internal store of IP addresses and local-device media access control(MAC)addresses. This store is known as the Address Resolution Protocol(ARP) cache. ARP is the universal tool for（5）IP addresses to MAC addresses. If the destination’s MAC address appears, the router installs that MAC address in the packet header(removing its own MAC address because that’s no longer needed)and sends the packet to the destination end station.

（1）A. up

B. down

C. sideward

D. back-fence

（2）A. via

B. through

C. by

D. through out

（3）A. special

B. especial

C. unique

D. particular

（4）A. accepter

B. sender

C. router

D. server

（5）A. searching

B. looking

C. locating

D. matching

相关考题：

In the open systems interconnection (OSI) reference model, "layer" means one of seven conceptually complete,(71) arranged groups of services, functions, and protocols, that extend across all open systems.Application layer provides means for the application(72) to access the OSI environment. Presentation layer provides for the selection of a common syntax for representing data.(73) layer provides the means necessary for cooperating presentation entities to organize and synchronize their dialog and to manage their data exchange. Transport layer provides a reliable end-to-end data transfer service. Network layer provides for the entities in the transport layer the means for transferring blocks of data, by(74) and switching through the network between the open systems in which those entities reside. Data link layer provides services to transfer data between network layer entities. Physical layer provides the mechanical, electrical, functional, and procedural means to establish, maintain and(75) physical connections for transfer of bits over a transmission medium.A．ranklyB．levellyC．layeredD．hierarchically
查看答案
TCP functions at the Open System Interconnection(OSI)(61)layer, or Layer 4. Its chief responsibility is to ensure(62)end-to-end connectivity. IP, located one layer down, at the OSI network layer, or Layer 3, communicates the addresses of each(63)sender and receiver to the routers along the way. Routers and Layer 3 switches can read IP and other Layer 3(64). This information, combined with routing tables and other network intelligence, is all it takes to get(65)the room or around the world via TCP/IP.A．transposeB．translateC．transmitD．transport
查看答案
A host computer has been correctly configured with a static IP address, but the default gateway is incorrectly set. Which layer of the OSI model will be first affected by this configuration error?A. Layer 1B. Layer 2C. Layer 3D. Layer 4E. Layer 5F. Layer 6E. Layer 7
查看答案
Which OSI layer is associated with the following: The acknowledgement of transmissions, sequencing, and flow control across a network?A. Layer 2B. Layer 3C. Layer 4D. Layer 5E. Layer 6F. Layer 7
查看答案
Acknowledgements, sequencing, and flow control are functions that are handled by which layer of the OSI model?A. Layer 5B. Layer 4C. Layer 7D. Layer 6E. Layer 3F. Layer 2G. Layer 1
查看答案
AtwhichlayeroftheOSImodeldoestheSpanningTreeProtocol(STP)operateat?() A.Layer5B.Layer4C.Layer3D.Layer2E.Layer1
查看答案
Acknowldgement, Sequencing, and Flow control are characteristics of which OSI layer?() A. Layer 2B. Layer 3C. Layer 4D. Layer 5E. Layer 6F. Layer 7
查看答案
PPP的执行在OSI模型哪个层?() A.Layer3B.Layer4C.Layer2D.Layer5
查看答案
Acknowledgements,sequencing,andflowcontrolarecharacteristicsofwhichOSIlayer?() A.Layer2B.Layer3C.Layer4D.Layer5E.Layer6F.Layer7
查看答案
Acknowledgements, sequencing, and flow control are characteristics of which OSI layer()。 A.Layer2B.Layer3C.Layer4D.Layer5E.Layer6F.Layer7
查看答案
热门标签