discuss the important responsibilities of data link layer in osi model

Tài liệu Module 7- Data Link Layer CCNA Exploration 4.0 pptx

... consists of virtual connections between the nodes of a network independent of their physical layout. – These logical signal paths are defined by Data Link layer protocols.• The Data Link layer ... www.bkacad.comConnecting Upper Layer Services to the Media11• To support a wide variety of network functions, the Data Link layer is often divided into two sublayers: an upper sublayer and an lower sublayer. ... Data Link Layer Protocols- The Frame31• Remember that although there are many different Data Link layer protocols that describe Data Link layer frames, each frame...

Tài liệu The Three Principles of Data Center Infrastructure Design pptx

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... Three Principles of Data Center Infrastructure DesignPage 5Choosing the Right Mix of EquipmentSince the total spend for network infrastructure equipment is but a fraction of the entire data ... percentage of terminations as copper, fiber optic cabling and connectivity is a significant part of the data center. Fiber links are also the most critical links because they carry data to and ... gain significant benefits and savings throughout the life of your data center. The Three Principles of Data Center Infrastructure DesignPage 7Deployment The graphic below depicts a sample data...

HUMAN RIGHTS AND THE MORAL RESPONSIBILITIES OF CORPORATE AND PUBLIC SECTOR ORGANISATIONS pptx

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... discourse. In the UK, the FTSE (The Financial Times Stock Exchange Index) has introduced in 2001 the FTSE4Good index for ethically high scorers. And this is just the latest in the line of a burgeoning ... economies. Identifying the ethical push behind entrenching the concept of minimum standards for corporate conduct in the sphere of international law Muchlinksi discerns a framework in which the moral ... consultancies. Discussion of the moral responsibilities of business has come out of the classroom and into both the financial press and the boardroom. Why? 9 J. Elkington, Cannibals with Forks: TheTtriple...

Báo cáo hóa học: " Editorial Cross-Layer Design for the Physical, MAC, and Link Layer in Wireless Systems" doc

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... these layers and their interaction. In recent years, the importance of the cross -layer design at the PHY/MAC /link layer has been reiterated through the emergence of manyinnovative techniques, ... information(e.g., the SNR information at the link layer or the queue sizeat the baseband module). The motivation for this special issue is the observationthat a cross -layer approach is particularly important ... cross -layer design hasbeen adopted. In short, the cross -layer methodology allowscertain important information to in uence decisions in a layer that is originally not deﬁned to use that information(e.g.,...

THE FRACTAL STRUCTURE OF DATA REFERENCE- P1 ppsx

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... TRANSACTION PROCESSING, Vijay Atluri, Sushil Jajodia, Binto George ISBN: 0-7923-7702-8FUZZY LOGIC IN DATA MODELING, Guoqing Chen ISBN: 0-7923-8253-6INTERCONNECTING HETEROGENEOUS INFORMATION ... /Moscow The Kluwer International Series on ADVANCES IN DATABASE SYSTEMS SeriesEditorAhmed K. Elmagarmid PurdueUniversityWest Lafayette, IN 47907 Other books in the Series: SEMANTIC MODELS ... 0-7923-7883-0 DATA DISSEMINATION IN WIRELESS COMPUTING ENVIRONMENTS, Kian-Lee Tan and Beng Chin Ooi; ISBN: 0-7923-7866-0MIDDLEWARE NETWORKS: Concept, Design and Deployment of Internet Infrastructure,...

THE FRACTAL STRUCTURE OF DATA REFERENCE- P2 pdf

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... Analysis of the Working Hypothesis 47 4. USE OF MEMORY AT THE I/O INTERFACE 511. Simulation using Time- in -Cache 52 3. Expectations for Memory Interaction 56 5. MEMORY MANAGEMENT IN AN LRU ... function of window size. 95 Requests to persistent cylinder images as a function of window size. 95 Requests to persistent files as a function of window size. 96 Distribution of file interarrival ... distinguish along a single time line. 6 1.2 Distribution of track interarrival times. Each curve shows a user or system storage pool at one of 11 sur-1.3 Distribution of page frame interarrival...

THE FRACTAL STRUCTURE OF DATA REFERENCE- P3 pptx

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... exploit them to best advantage. The emphasis of the book will be on the practical applications of such results. The focus of the applications examined in this book is on the portion of a computer ... example of such a phenomenon is not, by itself, sufficiently interesting to justify an entire book. Instead, the “meat” of the present book comes from the ability of the hierarchical reuse model ... based upon the explicitly hierarchical nature of most software. To reflect the inferred “behind the scenes” role of hierarchically structured soft-ware, we adopt, in Chapter 1, the term hierarchical...

THE FRACTAL STRUCTURE OF DATA REFERENCE- P4 pot

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... percent of the tracks. Since the beginning of the sorted list represents the best possible cache contents, we may apply the definition of Ω(l) to obtain the following upper bound on the hit ... Reuse Model 3 the LRU list, other than the requested track, remain linked together in the sameorder as before. This algorithm has the net effect that the tracks in the list always appear in order ... at the opposite end of the list, called the bottom, or Least Recently Used (LRU) position, is the track for which the longest time has passed since the previous reference. Therefore, in the LRUalgorithm,...

THE FRACTAL STRUCTURE OF DATA REFERENCE- P5 pps

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... than any of the time scales of interest (some fraction of one second). Thus, we will not bother trying to quantify the lower limit but simply note that there is one. In the remainder of the book, ... track does of being referenced in the next 20 seconds. Similarly, we should expect that the short term track has the same probability of being referenced in the next 1 minute, as the long-termtrack ... does of being referenced in the next 4 minutes. By formalizing the above example, we are now ready to state a specific hypothesis. Let the random variable U be the time from the last use of a...

THE FRACTAL STRUCTURE OF DATA REFERENCE- P6 ppsx

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... units of granularity. For example, the minidisk cache facility mentioned earlier manages data in units of one page frame (oneblock of 4096 bytes). The unit ofgranularity used in managing the ... size. Then we may conclude that the population of tracks currently visiting the cache is given by (1.13): THE FRACTAL STRUCTURE OF DATA REFERENCE Therefore,By contrast, measurements of the single-reference ... STRUCTURE OF DATA REFERENCE Let us first subdivide the entire visit into two parts: 1. The back end, starting with the last reference during the visit, and ending when the track is removed from the...

THE FRACTAL STRUCTURE OF DATA REFERENCE- P7 ppt

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... considering the require-ments of individual applications. In view of (1.20), such objectives provide a valuable starting point for configuration planning. Let us, therefore, consider the impact of the ... These include both the VM storage pools already introduced, as well as the stor-age pools traced during a survey oftwelve moderate to large OS/390 installations[ 17]. The figures include the ... reflected in the average or single-referenceresidency time). Our starting point for calculating the requirements for cache memory is Little’s law, as applied previously in the result (1.14). The...

THE FRACTAL STRUCTURE OF DATA REFERENCE- P8 pps

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... early demotion of sequential data residing in the cache; the memory for such data is typically freed long before the data would have progressed from the top to the bottom of the LRU list. Storage ... much the performance of the processor buffers themselves whichcomplicate the picture developed so far, since their performance can be de-scribed by the methods of analysis already discussed. Instead, ... prime indicates the miss ratio in the combined configuration. A more interesting configuration is one in which τc< τp. In this environ-ment, a “division of labor” becomes possible, in...

THE FRACTAL STRUCTURE OF DATA REFERENCE- P9 ppt

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... applying (1.26), that the processor miss ratio must be evaluated at the single-reference residency time of the storage control cache). Plugging (1.4) into (1.26), we find that, for reads, in the ... constant. In the region < however, the plot should show reduced responsiveness, reflecting the reduced exponent appearing in (1.27). Also, the transition between the two regions of the curve ... virtually the entire line of reasoning presented in the previous subsections extends to the case of reads to a cache, where processor buffers are present. Corresponding to (1 .2 1), we obtain(1.28)whereprovided...

THE FRACTAL STRUCTURE OF DATA REFERENCE- P10 potx

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... as an independently executing “daemon” [19], and provides a natural building block forI/O performance testing. In addition, it helps bring to life, in the form of a concrete example, the hierarchical ... alternative method of characterizing the hierarchical reuse model, which 34 THE FRACTAL STRUCTURE OF DATA REFERENCE Notes1 Assumes a track belonging to the 3380 family of storage devices. ... behavior synthetically. Finally, we illustrate the actual behavior of the proposed synthetic requests through simulation. 1. DESIRED BEHAVIOR Assuming that a pattern of requests obeys the hierarchical...

THE FRACTAL STRUCTURE OF DATA REFERENCE- P11 pot

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... (2.2). The method of performing the needed random walk can be visualized by thinking of the available tracks as being the leaves of a binary tree, of height Hmax. The ancestors of any given ... specifically on the most interesting region of interarrival times (those in the range of 32–512 seconds), all of the curves appear to have settled into a close approximation of the predicted ... obtained by dropping the last two binary digits of the number l; and all tracks have the same great-grandparent.Starting from a given leaf li of the tree, the next leaf li+1is determined...