data link layer switching computer networks ppt

... Data Link Layer Protocols- The Frame 31 • Remember that although there are many different Data Link layer protocols that describe Data Link layer frames, each frame ... logical signal paths are defined by Data Link layer protocols. • The Data Link layer "sees" the logical topology of a network when 24 • The Data Link layer "sees" the logical ... chapter, you will be able to: • Explain the role of Data Link layer protocols in data transmission. • Describe how the Data Link layer prepares data for transmission on network media. • Describe...

Ngày tải lên: 22/12/2013, 13:17

... Andrew S. Tanenbaum, Computer Networks, Pearson Education International, Fourth Edition – 2003 [2] Joseph L. Hammond, Peter J. P. O’Reilly, Performance Analysis of Local Computer Networks, Addison-Wesley ... Edition – Prentice Hall 2000 [4] William Stalling, Data and Computer Communications, Prentice Hall, Fifth Edition, 1997 [5] Jim Kurose, Keith Ross, Computer Networking: A Top-Down Approach Featuring ... Inteternet. Môn này khảo sát các đặc tính và cơ chế của mạng từ lớp liên kết (Link Layer) đến lớp ứng dụng (Application Layer) không chỉ định tính mà còn định lượng. Qua môn học này, sinh viên sẽ...

Ngày tải lên: 24/01/2014, 04:20

... faster. Layer 3 – The Network Layer Layer 3, the network layer of the OSI model, provides an end-to-end logical addressing system so that a packet of data can be routed across several layer 2 networks ... four layers to perform the functions of the seven -layer OSI model. The network access layer is functionally equal to a combination of OSI physical and data link layers (1 and 2). The Internet layer ... The Physical Layer of the OSI model is only part of a LAN (Local Area Network). Layer 2 – The Data Link Layer Layer 2 of the OSI model provides the following functions: • Allows a device to access...

Ngày tải lên: 24/01/2014, 09:20

Ngày tải lên: 23/10/2014, 21:01

Ngày tải lên: 22/10/2013, 16:44

... trường hợp về sự cố mạng có thể do phần cứng hay phần mềm: Phần cứng (Lớp Physical, Data Link) : Đèn liên kết (Link ) của card mạng không sáng Kiểm tra đầu nối card mạng và đầu cáp nối trên HUB/SWITCH ...

Ngày tải lên: 23/12/2013, 03:17

... same data access technologies as that of the nontransactional DAL. The following data access technologies were covered in Module 8, “The Nontransactional Data Access Layer : ! Microsoft Data ... DAL. Module 9: The Transactional Data Access Layer 3 The Business Problem DAL Connected Business Logic Layer Disconnected Business Logic Layer Facade Layer Web Services Facade Business ... data services layer. The transactional DAL can return to the business logic layer either success or failure. If the transaction also involved retrieving data as a result of updates to the data, ...

Ngày tải lên: 17/01/2014, 09:20

... } foreach $links (keys (%uniql)){ qprint "External link $uniql{$links} : $links\n"; } foreach $links (keys (%uniqm)){ qprint "External email $uniqm{$links} : $links\n"; ... OK Bag Attributes - 41 - Breaking into computer networks from the Internet [Roelof Temmingh & SensePost] that is just as sensitive as the data that you will find on a corporate internal ... configured. ID systems looks for patterns or signatures in datastreams. If the pattern in the datastream matches that of a pattern in the IDS's database (that is marked as "bad") the...

Ngày tải lên: 24/01/2014, 09:20

... Recipe 1.13 Using the Data Link Properties Dialog Box Problem You want to display the Data Link Properties dialog b ox from an application so that users can create their own database connections ... Reference Dialog. The sample code contains a single event handler: Data Link Dialog Button.Click Creates and displays a Data Link Properties dialog box using the Microsoft OLE DB Service Component ... shown in Example 1-10 . Example 1-10. File: DataLinkDialogForm.cs // Namespaces, variables, and constants using System; // . . . private void dataLinkDialogButton_Click(object sender, System.EventArgs...

Ngày tải lên: 26/01/2014, 10:20

... i  Transmitter goes back to frame i and retransmits William Stallings Data and Computer Communications Chapter 7 Data Link Control Cyclic Redundancy Check  For a block of k bits transmitter ... Protocols (LAPB,LAPD)  Link Access Procedure, Balanced (LAPB)  Part of X.25 (ITU-T)  Subset of HDLC - ABM  Point to point link between system and packet switching network node  Link Access Procedure, ... frames  Three phases  Initialization  Data transfer  Disconnect Control Field  Different for different frame type  Information - data to be transmitted to user (next layer up)  Flow and error control...

Ngày tải lên: 16/02/2014, 08:20

... a data packet, and hence, the shorter the blocking time will be for other links in link l jk ’s collision domain. Also, the smal- ler I jk is, the fewer number of links is interfered by the link ... integrates the AMC technology and the antenna type at the PHY layer, TMCR at the network layer, MAC scheduling and WLA at the data link layer to derive a cost effective WMN design. CMRP encapsulates ... placement, multi-hop relay networks, relay node placement, wireless mesh networks, wireless multi-hop networks 1 Introduction In the near future, broadband wireless mesh networks (WMNs) [1,2] are...

Ngày tải lên: 20/06/2014, 22:20

... proposed estimators are “non -data aided” and only rely on a physical layer processing so that they do not require m ulti- mode termi nals to be first connected to the handover candidate networks. Results ... interfaces have to determine which networks can be used and the services avai lable in each network. These wireless networks may also advertise the sup- ported data rates for different services. ... influence of the data rate on the channel occupancy rate. For three Client/Server systems, we plot the channel occupancy rate f or different data rat e. Each system us es the same data rate. We...

Ngày tải lên: 21/06/2014, 00:20

... this paper we address the problem of data association in visual sensor networks. We consider data association as an inference problem in dynamic Bayesian networks, where a higher-order spatiotemporal ... centralized approach in that it needs to collect all data into a data processing center. This is unsuitable for large-scale visual sensor networks. Nowadays, smart camera emerges which is not ... unknown and need to be estimated with data association algorithms. Considering the hidden labels as missing data, the problems of parameter estimation and data association can be solved simultaneously under...

Ngày tải lên: 21/06/2014, 05:20

... C 3 in multihop wireless networks. The management behavior mainly contains two operations: one is the data replacement, and the other is the data retrieval. 4.1. Data Replacement. When a new data segment ... buffer management [22], energy improvement in wireless networks [23], data gossiping [24], as well as data dissemination in sensor networks [11] and in peer-to-peer networks [15]. For storage systems, various ... After the data replacement with new data segment c i , the probability of a combined data segment having cardinality 1 <  k<iremains unchanged. The probability of a combined data segment...

Ngày tải lên: 21/06/2014, 17:20

... wireless sensor networks suffers from lack of real system deployments and available data experiments. Researchers often evaluate their algorithms and protocols with model-driven data [38]. Here, ... wireless sensor networks, ” IEEE/ACM Transactions on Networking, vol. 14, no. 2, pp. 316– 329, 2006. [13] A. Jindal and K. Psounis, “Modeling spatially correlated data in sensor networks, ” ACM ... networks, ” in Handbook of Sensor Networks, I. Stojmenovic, Ed., 2005. [37] G. Mao, B. Fidan, and B. D. O. Anderson, “Wireless sensor network localization techniques,” Computer Networks, vol. 51, no. 10,...

Ngày tải lên: 21/06/2014, 17:20

... Efficiency  =  M R =0 n R data n R data + n hdr ·Pr  Frame received correctly  · Pr  R retransmission in history window M  , (11) where n R data is the size of frame data for R retransmissions ... the energy efficiency of PLO: E  1 − hop Energy Efficiency  =  M R =0 n R data n R data + n hdr · ⎛ ⎝ M R ⎞ ⎠  ε n R data  R  1 − ε n R data  M−R+1 . (13) Assuming independence between each hop, (13)canbe extended ... Efficiency  = H  m=1  M ( m ) R ( m ) =0 n R ( m ) data n R ( m ) data + n hdr · ⎛ ⎝ M ( m ) R ( m ) ⎞ ⎠  ε n R ( m ) data  R ( m )  1 − ε n R ( m ) data  M (m) −R (m) +1 , (14) where superscript...

Ngày tải lên: 21/06/2014, 22:20

... Networking Network layer Link quality measurement iTolerance info exchange MiRii routing protocol TxPower level selection iTolerance calculation Physical layer Figure 2: The cross -layer routing protocol ... on a perflow basis. The network layer coor- dinates with the physical layer to choose the appropriate transmission power level and to find a routing path with better link quality. The proposed M 2 iRi 2 routing ... sequence number Σ ETT link Σ chanETT link Σ AT node Fid TxPower Figure 3:TheformatofRREQpacket. adjusts the transmission power level for this trafficflowto forward to the next hop. The data transmission...

Ngày tải lên: 21/06/2014, 23:20

Ngày tải lên: 21/06/2014, 23:20

Ngày tải lên: 22/06/2014, 10:20