问题 单项选择题

下列关于路由器技术指标的描述中,错误的是()。

A.路由器端口吞吐量是指其某个具体端口的包转发能力

B.路由器应能支持DiffServ、RSVP与MPLS等QoS协议类型

C.高速路由器一般要求长度为1518B的IP包,延时要小于100ms

D.路由器的网管能力可以管理到端口、网段、IP地址或MAC地址

答案

参考答案:C

解析:

[考点透解] 延时是指数据帧的第一个比特进入路由器,到该帧的最后一个比特离开路由器所经历的时间。高速路由器一般要求长度为1518B的IP包,延时要小于1ms。据此,选项C的说法有误。 吞吐量是指路由器的包转发能力,与其端口数量、端口速率、包长度、包类型有关,涉及端口吞吐量与整机吞吐量两个方面的内容。端口吞吐量是指路由器某个具体端口的包转发能力,而整机吞吐量是指路由器整机的包转发能力。 路由器的服务质量主要表现在队列管理机制、端口硬件队列管理与支持的QOS协议(如区分服务协议(DiffServ)、资源预留协议(RSVP)与多协议标记交换协议(MPLS)等)类型上。 路由器的网络管理粒度标志着路由器管理的精细程度。其网管能力可以管理到端口、网段、IP地址或MAC地址。

单项选择题
阅读理解

“I’m a little worried about my future.”said Dustin Hoffman in The Graduate.He should be so lucky.All he had to worry about was whether to have an affair with Mrs. Robinson.In the sixties,that was the total sum of post-graduation anxiety.

Hoffman’s modem peers are not so fortunate.The Mrs. Robinsons aren’t sitting around at home any more.They are out in the workplace,doing the high-powered jobs the graduates want,but cannot get.For those fresh out of university,desperate for work but unable to get it,there is a big imbalance between supply and demand.And there is no narrowing of the gap in sight.

Parents feel as badly let down as the young people themselves.Middle-class families see their graduate offspring on the dole (救济金) queue and wonder why they bothered paying school fees.Working-class families feel an even keener sense of disappointment.For many such families,getting a child into university was the fulfillment of a lifelong dream.It was proof that they were living in a dynamic,economically successful country.That dream does not seem so rosy now.Graduate unemployment is not,ultimately,a political problem.Job-creation for graduates is very low down in the government’s schedule.If David Cameron’s Conservatives (保守党) had a brilliant idea for guaranteeing every graduate a well-paid job,they would have presented it by now.It is a social problem,though a more deep-seated social problem than people perhaps realize.

小题1:The author begins with the lines from The Graduate in order to __________ .

A.support the fact that more women are working now

B.show that few graduates started working right after graduation

C.demonstrate that there were much fewer graduates than now

D.emphasize the sharp contrast between now and then小题2:Regarding job opportunities for young graduates,the author sounds __________ .

A.pessimistic

B.hopeful

C.unconcerned

D.content小题3:The main purpose of the passage is to __________ .

A.criticize the government

B.present a current severe situation

C.publicize a movie

D.display the success of the country小题4:Towards the end of the passage,the author implies that __________ .

A.there will be job-creation programs for graduates

B.graduate unemployment is more of a political issue

C.graduate unemployment is not likely to be solved in a short time

D.the Conservatives have done nothing to solve the issue