Đang chuẩn bị liên kết để tải về tài liệu:
CompTIA Network+ Certification Study Guide part 28

CompTIA’s Network+ certification Study Guide part 28 is a globally-recognized, vendor neutral exam that has helped over 235,000 IT professionals reach further and higher in their careers. The 2009 Network+ exam (N10-004) is a major update with more focus on security and wireless aspects of networking. Our new study guide has been updated accordingly with focus on network, systems, and WAN security and complete coverage of today’s wireless networking standards. | 256 CHAPTER 6 The OSI Model and Networking Protocols The TDI Boundary Layer The TDI provides a portal into the transport protocols for kernel mode components such as servers and redirectors. In essence it is the gateway between the transport layer and the session layer in the OSI model providing a common interface developers can use to access both transport and session layer functionality. The API Boundary Layer The API is the interface through which developers can access network infrastructure services such as various application layer protocols. Dynamic Host Configuration Protocol DHCP DNS and Windows Internet Name Service WINS all work at this level and connect to the lower layers through APIs. There are also Windows Sockets WinSock NetBIOS telephony and messaging APIs used to assist in carrying out lower-level network functions. Understanding Component Layers Within each layer are component layers that provide very specific functionality. The NDIS Wrapper The NDIS wrapper is a library of common NDIS functions that can be used both by the MAC protocols beneath it and by TCP IP above it. The NDIS wrapper is implemented by a file called Ndis.sys which is software code that surrounds all NDIS device drivers. It provides a common interface for device and protocol drivers. The NDIS wrapper is used to reduce platform dependencies during development of network interface devices. Network Transport Protocols Network Transport Protocols all applications or clients to send and receive data over the network. Other network transport protocols include IPX SPX Asynchronous Transfer Mode ATM NetBEUI Infrared Data Association IrDA AppleTalk and SNA. These protocols are used on a variety of non-Microsoft operating systems including Novell Apple and IBM. File System Drivers The file system drivers are the Redirector and the Server service. When there is a request to open a shared file the I O Manager sends a request to the Redirector which selects the appropriate transport layer .