The TCP protocolis a （）layer pr

TCP/IP(71)layer protocols provide services to the application(72)running on a computer. The application layer does not define the application itself, but rather it defines(73)that applications need--like the ability to transfer a file in the case of HTTP. In short, the application layer provides an(74)between software running on a computer and the network itself. The TCP/IP application layer includes a relatively large number of protocols, with HTTP being only one of those. The TCP/IP(75)layer consists of two main protocol options--the Transmission Control Protocol(TCP) and the User Datagram Protocol(UDP).

A．application

B．transport

C．link

D．network

Each machine supporting TCP has a TCP transport entity, either a library procedure, a user process, or part of the kernel. In all case, it manages TCP streams and (71) to the IP layer. A TCP (72) accepts user data streams from local process, breaks them into pieces not exceeding 64KB, and sends each piece as a separate IP (73). When datagrams containing TCP data arrive at a machine, they are given to the TCP entity, which reconstructs the original byte streams.The IP layer gives no guarantee that datagrams will be delivered properly, so it is up to TCP to time out and (74) them as need be. Datagmms do arrive may well do so in the wrong order, it is also up to TCP to (75) them into messages in the proper sequence.

A．calls

B．interfaces

C．links

D．produces

A.Application Layer、PPP、TCP/IP、RLP，Physical Layer

B.Application Layer、PPP、RLP、TCP/IP、Physical Layer

C.Application Layer、RLP、PhysicalLayer、TCP/IP、PPP

D.Physical Layer、RLP、PPP、TCP/IP、Application Layer

● TCP/IP （71） layer protocols provide services to the application （72） running on a computer. The application layer does not define the application itself, but rather it defines （73） that applications need—like the ability to transfer a file in the case of HTTP. In short, the application layer provides an （74） between software running on a computer and the network itself. The TCP/IP application layer includes a relatively large number of protocols, with HTTP being only one of those. The TCP/IP （75） layer consists of two main protocol options—the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP).

The TCP protocol is a （72）layer protocol．

A.physical

B.network

C.transport

D.application

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．transpose

B．translate

C．transmit

D．transport

● TCP/IP communication protocol contains four layers. From bottom to top, the four layers are __(71)__.

（71）A．network interface layer, internet layer, transport layer and application layer

B．internet layer, network interface layer, transport layer and application layer

C．network interface layer, transport layer, network interface layer and application layer

D．application layer, transport layer, internet layer and network interface layer

A.physical

B.network

C.transport

D.application

TCP/IP is a communication protocol, which provides many different networking services. The TCP/IP Internet protocol suite is formed from two standards: the TCP （Transmission Control Protocol） and the IP（Internet Protocol）.

（72） means it is on the transport layer.

A.ISO

B.IP

C.OSI

D.TCP

is a connectionless TCP/IP transport layer protocol.

A．FTP

B．UDP

C．1P

D．ICMP