作业帮 > 英语 > 作业

英语翻译• Connection-oriented:This is normally easier to d

来源:学生作业帮 编辑:拍题作业网作业帮 分类:英语作业 时间:2024/05/23 01:39:01
英语翻译
• Connection-oriented:This is normally easier to deal with than connection-less models,so where the Network layer only provides a connection-less service,often a connection-oriented service is built on top of that in the Transport Layer.
• Same Order Delivery:The Network layer doesn't generally guarantee that packets of data will arrive in the same order that they were sent,but often this is a desirable feature,so the Transport Layer provides it.The simplest way of doing this is to give each packet a number,and allow the receiver to reorder the packets.
• Reliable data:Packets may be lost in routers,switches,bridges and hosts due to network congestion,when the packet queues are filled and the network nodes have to delete packets.Packets may be lost or corrupted in Ethernet due to interference and noise,since Ethernet does not retransmit corrupted packets.Packets may be delivered in the wrong order by an underlying network.Some Transport Layer protocols,for example TCP,can fix this.By means of an error detection code,for example a checksum,the transport protocol may check that the data is not corrupted,and verify that by sending an ACK message to the sender.Automatic repeat request schemes may be used to retransmit lost or corrupted data.By introducing segment numbering in the Transport Layer packet headers,the packets can be sorted in order.Of course,error free is impossible,but it is possible to substantially reduce the numbers of undetected errors.
• Flow control:The amount of memory on a computer is limited,and without flow control a larger computer might flood a computer with so much information that it can't hold it all before dealing with it.Nowadays,this is not a big issue,as memory is cheap while bandwidth is comparatively expensive,but in earlier times it was more important.Flow control allows the receiver to say "Whoa!" before it is overwhelmed.Sometimes this is already provided by the network,but where it is not,the Transport Layer may add it on.
连接型:这比无联系的模型通常是容易处理,因此网络层只提供一项无联系的服务的地方,一项连接型服务经常被建立在那顶部在传送层.
•同样命令交付:网络层通常不保证数据包按同一顺序将到达送了他们,但是经常这是一个中意的特点,因此传送层提供它.单一方式做此将给每个小包数字,并且允许接收器重新命令小包.
•可靠的数据:小包在路由器、开关、桥梁和主人也许丢失由于网络堵塞,当小包队列被填装时,并且网络节点必须删除小包.因为以太网不转播腐败的小包,小包在以太网也许丢失或腐败由于干涉和噪声.小包也许按错误顺序被交付通过一个部下的网络.一些传送层协议,例如TCP,可能固定此.通过错失侦查代码,例如检查和,运输协议也许检查数据没有腐败和通过寄发ACK消息核实那到发令者.自动请求重发计划也许被用于转播失去或腐败的数据.通过介绍在传送层包标头的段编号,小包可以按顺序被排序.当然,无错是不可能的,但是极大地减少未被发现的错误的数量是可能的.
•流程控制:相当数量在计算机上的记忆是有限的,并且,不用流程控制一台大规模计算机也许非常充斥计算机与信息它不可能在涉及举行它全部它之前.现今,这不是一个大问题,因为记忆是便宜的,当带宽是相当地昂贵的时,但是在更加早期的时期是更加重要的.流程控制允许接收器说“Whoa!” 在它之前被淹没.有时网络已经提供这,但是它不的地方,传送层也许增加它.
100/100正确