关于UDP的一题问题

蓝色飞鱼

<P>The corporate head office of TestKing has a teleconferencing system that uses VOIP<BR>(voice over IP) technology. This system uses UDP as the transport for the data<BR>transmissions. If these UDP datagrams arrive at their destination out of sequence,<BR>what will happen?<BR>A. UDP will send an ICMP Information Request to the source host.<BR>640 - 801<BR>Leading the way in IT testing and certification tools, <A href="http://www.testking.com/">www.testking.com</A><BR>- 445 -<BR>B. UDP will pass the information in the datagrams up to the next OSI layer in the<BR>order that they arrive.<BR>C. UDP will drop the datagrams.<BR>D. UDP will use the sequence numbers in the datagram headers to reassemble the<BR>data in the correct order.<BR>E. UDP will not acknowledge the datagrams and wait for a retransmission of the<BR>datagrams.</P><P>&nbsp;</P><P>&nbsp;这题该怎么选，UDP包具体是怎么传输的？？</P><P>&nbsp;</P><p>［此帖子已被 蓝色飞鱼 在 2005-8-23 12:33:13 编辑过］

快乐孤儿

<P>UDP是不可靠的,无确认,不丢弃,它会直接把数据交给上层处理.</P><P>例如QQ使用的就是UDP,有时候网络繁忙,你收到的可能是5分钟之前的消息,但是你毕竟还是收到了,是不是?</P><P>所以应该选B,</P>

single

<IMG src="http://www.spoto.net/bbs/images/Emotions/72.gif">谢谢