What are three characteristics of UDP?（）A、UDP is faster than TCPB、UDP operates at the Transport LayerC、UDP is connection-orientedD、UDP data is sent best-effortE、UDP is more reliable than TCP

A.TCP is a transport layer protocol.

B.TCP is faster than the User Datagram Protocol (UDP).

C.TCP provides delivery notification and error checking mechanisms.

D.TCP uses a best effort delivery approach.

E.TCP application examples include HTTP and SMTP.

以下关于 TCP/IP协议栈中协议和层次对应关系的叙述中，正确的是（ ）。

A. TFTP Telnet UDP TCP ARP B. RIP Telnet UDP TCP ARP C. HTTP SNMP TCP UDP IP D. SMTP FTP UDP TCP IP

下列关于TCP和UDP的描述正确的是______。

A．TCP和UDP均是面向连接的

B．TCP和UDP均是无连接的

C．TCP是面向连接的，UDP是无连接的

D．UDP是面向连接的，TCP是无连接的

A.TCP 135

B.TCP/UDP 135

C.UDP 135

D.TCP/UDP 153

A.TCP502

B.TCP514

C.TCP520

D.UDP502

E.UDP514

F.UDP520

A. UDP is faster than TCP

B. UDP operates at the Transport Layer

C. UDP is connection-oriented

D. UDP data is sent best-effort

E. UDP is more reliable than TCP

The corporate head office of TestKing has a teleconferencing system that uses VOIP (voice over IP) technology. This system uses UDP as the transport for the data transmissions. If these UDP datagrams arrive at their destination out of sequence,what will happen?（）

A. UDP will send an ICMP Information Request to the source host.

B. UDP will pass the information in the datagrams up to the next OSI layer in the order that they arrive.

C. UDP will drop the datagrams.

D. UDP will use the sequence numbers in the datagram headers to reassemble the data in the correct order.

E. UDP will not acknowledge the datagrams and wait for a retransmission of the datagrams.

A.UDP provides delivery notification and error checking mechanisms.

B.UDP is faster than the Transmission Control Protocol (TCP).

C.UDP application examples include DNS and VoIP.

D.UDP is an application layer protocol.

E.UDP uses a best effort delivery approach.

A.TCP502

B.TCP514

C.TCP520

D.UDP502

E.UDP514

F.UDP520