osi layers

OSI reference model and troubleshooting The bottom layer of the OSI reference model provides services for its upper layer. Therefore, troubleshooting should also be performed from the bottom layer to the upper layer. If you are an IT support staff member of a company and an employee calls to say that the webpage cannot be opened, what should you do? 1) physical layer check. First, check whether the netwo

Regular Test of preliminary roundFirst, we need to know the correspondence between the two models.There is a very good picture:Then we select the more detailed OSI model to easily understand the analysis(1) Physical layer: mainframe and the like(2) Data link layer: Signal walking route (network cable, etc.)(3) Network layer: The path from the host to the place where the signal is to go(4) Transport layer: the signal goes through the process of each se

The role of each layer of the OSI Reference ModelPhysical layer: Transmits the raw data bitstream on the physical media.Data Link layer: Divides data into data frames and transmits them in a data frame. There should be a reply, the wrong re-hair.Network layer: The data is divided into a certain length of grouping, will be grouped through the communication subnet, select a path from the source to upload to the message.Transport layer: An efficient, cos

host scan discovery via OSI layer three (network layer)OSI The third layer of the model is the data link layer, where the protocols that work primarily are IP and ICMP. You can use different IP protocols to send different packages to the target host. You can also use different ICMP requests to determine if the target host is online. Network layer To establish a reply between the commun

Application layer: HTTP Application layerPresentation layer: Coding presentation LayerSession Layer: Port Session LayerTransport Layer: TCP/UDP Protocol Transport LayerNetwork layer: IP tag +--Network layer--+ Network layerData Link layer: Computer MAC address Tag |　　　| Data Link LayerPhysical layer: Network cable, Crystal Head, computer socket | +----> Physical layer+------------------------------------->+"The bottom layer serves the upper layer and is transparent, and the corresponding protoco

]) * (Y[b]-Y[a]); - } - - intMain () { + intT; -scanf"%d", t); + while(t--) { A intN; atscanf"%d", n); - for(inti =0; I "%d%d", x[i], y[i]); - for(inti =0; I 1|1] = Dis (i, (i +1) %n); - for(inti =0; I 1] = Cross (i, (i-1+ N)% n, (i +1) %n); - intAll = N 1; for(inti =0; I 1; - intAns =0, mx =0, id =0; Memset (P,0,sizeof(P)); in for(inti =0; i ) { -P[i] = mx > I? Min (P[id *2-i], mx-i):1; to while(I-p[i] >=0 i + P[

called a segment. Session Layer: Establish, manage, and terminate sessions. That is, through the transport Layer (port number: Transport port and receive port) to establish the path of data transmission, mainly between your system to initiate a session or accept a session request (between the devices need to know each other can be IP or Mac or host name). Presentation layer: For data conversion, compression, and encryption. The ensures that the information sent by the application layer of

OSI Virtual Machine Model "Virtual" means that although an object or device does not exist at a certain time, people can see it. The word "Virtual Machine" is easy for many people to think about. Pop Media and News Broadcasts often use the word "virtual" when reporting new developments in computer simulation and computer games. In any situation, the use of "virtual" means that although an object or device does not exist at a certain t

label: des style blog HTTP color Io OS AR for 1100: [POI2007]对称轴osiTime Limit:10 SecMemory Limit:162 MB Submit:334Solved:130 [Submit][Status] Description FGD小朋友——一个闻名遐迩的年轻数学家——有一个小MM，yours。FGD小朋友非常喜欢他的MM，所以他很乐意帮助他的MM做数学作业。但是，就像所有科学的容器一样，FGD的大脑拒绝不停地重复思考同样的问题。不幸的是，yours是一个十分用功的学生，所以她不停地让FGD帮助她检查她的作业。一个阳光明媚的周末，yours的数学老师布置了非常多的寻找多边形的对称轴的题，足够她做相当长的一段时间了。在此之前FGD已经决定去海边度过这个难得的假期，不过他还是觉得应该帮助他的MM对付可爱的数学作业。很快地，他找到了解决方案，最好写一个程序来帮助yours检查她的数学作业。因为FGD并非一个计算机科学家，所以他找到了他的好朋友你，请你帮助他完成这个任务。请写一个程序：读入多边形的描述计算

These are my interpretations of OSI. They are not very rigorous, but very simple:① Physical layer: define what is 0 and what is 1② Link layer: communication between two points directly connected through Homogeneous Media (Use MAC address)③ Network layer: any connected communication between two points (Use IP Address)④ Transport layer: reliable communication between any connected two points (Port Number)⑤ Session Layer: establish and manage communicati

[TechTarget China original] OSI Mode layer 4th is the transport layer, which is located in the middle of the OSI Mode. This chapter describes fingerprint recognition and its relationship with the transport layer. Fingerprint recognition is an operating system (OS)-level function. To better understand how fingerprint recognition works, we first need to review some basic concepts of the transport layer: ident