data link layer definition

... Data Link Layer Protocols- The Frame 31 ã 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. ã The Data Link layer "sees" the logical topology of a network when 24 ã The Data Link layer "sees" the logical ... chapter, you will be able to: ã Explain the role of Data Link layer protocols in data transmission. ã Describe how the Data Link layer prepares data for transmission on network media. ã Describe...

Ngày tải lên: 22/12/2013, 13:17

Ngày tải lên: 04/04/2014, 12:28

Ngày tải lên: 23/10/2014, 21:01

... with other frames sent in [t 0 -1,t 0 +1] 5: DataLink Layer 5-2 Chapter 5: The Data Link Layer Our goals: ❒ understand principles behind data link layer services: ❍ error detection, correction ❍ sharing ... etc ❍ extracts datagram, passes to rcving node ❒ adapter is semi- autonomous ❒ link & physical layers sending node frame rcving node datagram frame adapter adapter link layer protocol 5: DataLink Layer ... multiple access ❍ link layer addressing ❍ reliable data transfer, flow control: done! ❒ instantiation and implementation of various link layer technologies 5: DataLink Layer 5-49 Star topology ❒ Bus...

Ngày tải lên: 12/09/2012, 15:06

... + HF – (thoại tương tự) + VHF Data link: VDL Mode2 – (dữ liệu), VDL mode3 - (thoại và dữ liệu), và VDL mode4 - (dữ liệu). + SSR Mode S - (dữ liệu) + HF Data link – (dữ liệu). Các dịch vụ thông ... trên vùng lãnh thổ Việt Nam. Luận văn “ ỨNG DỤNG CỦA VHF DATA LINK MODE 4 TRONG MÔI TRƯỜNG CNS/ ATM ” nghiên cứu công nghệ kỹ thuật VHF Data Link Mode 4, một liên kết dữ liệu số sử dụng sóng VHF ... phân lớp điều khiển truy nhập MAC ( Medium Access Control ), Dịch vụ liên kết dữ liệu DLS ( Data Link service ) và thực thể quản lý liên kết ( LME ). Lớp liên kết dữ liệu VDL cung cấp sự truyền...

Ngày tải lên: 22/11/2012, 09:13

Ngày tải lên: 23/08/2013, 10:37

... CHAPTER 8 ■ DATA ACCESS LAYER 174 private void DisconnectFromDatabase() { if (_databaseConnection.State != ConnectionState.Open) { _databaseConnection.Close(); } } private IDataReader ... CreateUserFromReader(IDataReader dataReader) { int id = dataReader.GetInt32(0); string name = dataReader.GetString(1); string emailAddress = dataReader.GetString(2); string password = dataReader.GetString(2); ... the project, only the parts of the database that are in use by the object model should have been generated. CHAPTER 8 ■ DATA ACCESS LAYER 164 DATABASE KEYS Database tables should always have...

Ngày tải lên: 03/10/2013, 01:20

... modules that focus on the data access layer (DAL). In Module 8, “The Nontransactional Data Access Layer, ” you learned about data retrieval. In this module, you will learn about data manipulation. ... 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 8, “The Nontransactional Data Access Layer and Module 9, “The Transactional Data Access Layer. ” The DAL is an application’s means of access to data services. After completing this...

Ngày tải lên: 05/11/2013, 12:15

... Nontransactional Data Access Layer 15 Data Shaping Service ! Relation-based Hierarchical Rowsets ! Group-based Hierarchies ! Using Data Shaping ! Sample Definition OLE DB provides a Data Shaping ... is any component that owns data. It exposes its data in a tabular format, regardless of the format in which it stores data. Examples of data providers are relational database management systems ... Nontransactional Data Access Layer # ## # Introduction to the Data Access Layer ! The Business Problem ! Splitting the DAL The DAL buffers the entire system from the underlying data services....

Ngày tải lên: 21/12/2013, 06:17

... 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

... 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

... serves as both ACK 2 and ACK 3. 11.2 11-1 FRAMING 11-1 FRAMING The data link layer needs to pack bits into The data link layer needs to pack bits into frames frames , so , so that each frame ... sender events. Request events are triggered by data from the network layer; arrival events are triggered by acknowledgments from the physical layer. There is no time-out event here because ... This is an example of a case where the forward channel is reliable, but the reverse is not. No data frames are lost, but some ACKs are delayed and one is lost. The example also shows how cumulative...

Ngày tải lên: 16/02/2014, 20:20

... receiver  Error detection at MAC layer  32 bit CRC  Destination and source access points (DSAP, SSAP) 2 Introduction  Data link control layer – often abbreviated simply to data link layer – is concerned ... 50 Bit-oriented Protocols – HDLC (High-level Data Link Control) 3 Introduction  Depending on the application, the user service provided by the data link layer may be either a simple best-try ... service DATA LINK CONTROL PROTOCOLS 26 Character-oriented Protocols – Half-duplex Protocols  BSC 49 Bit-oriented Protocols – HDLC (High-level Data Link Control)  Protocol operation  Link...

Ngày tải lên: 30/03/2014, 07:20

Ngày tải lên: 21/06/2014, 22:20

Ngày tải lên: 21/06/2014, 22:20

Ngày tải lên: 08/08/2014, 10:20

Ngày tải lên: 08/08/2014, 10:20