Windows Network学习笔记
术语：
1． NDIS：Network Driver Interface Specification
2． NIC：Network Interface Card
3． TDI：Transport Driver Interface
4． OSI：Open Systems Interconnection
1． The OSI Reference Model
1．Physical Layer
reception and transmission of the unstructured raw bit stream over a physical medium.，It describes the electrical/optical, mechanical, and functional interfaces to the physical medium. The physical layer carries the signals for all the higher layers. Under Windows 2000, the physical layer is implemented by the network interface card (NIC), its transceiver, and the medium to which the NIC is attached. For network components that use serial ports, the physical layer can also include low-level network software that defines how the serial stream of bits is divided into packets of data.
2．Data Link Layer
1． MAC layer
checks frame errors, and manages address recognition of received frames,implemented in the network interface card (NIC). The NIC is controlled by a software device driver called the NIC driver.
2． LLC layer
provides error-free transfer of data frames from one node to another,establishes and terminates logical links, controls frame flow, sequences frames, acknowledges frames, and retransmits unacknowledged frames,implemented in the transport driver
3．Network Layer
This layer controls the operation of the subnet. It determines the physical path the data should take, based on the following:
· network conditions
· priority of service
· other factors, including routing, traffic control, frame fragmentation and reassembly, logical-to-physical address mapping, and usage accounting
implemented in the transport driver
4．Transport Layer
ensures that messages are delivered error-free, in sequence, and with no loss or duplication.，A minimal Transport Layer is required in protocol stacks that include a reliable Network or Logical Link Control sublayer that provides virtual circuit capability. For example, because the Windows 2000 NetBEUI transport driver includes an OSI-compliant LLC sublayer, its Transport Layer functions are minimal. If the protocol stack does not include an LLC sublayer, and if the Network Layer is unreliable and/or supports datagrams (as with TCP/IP's IP layer or NWLink's IPX layer), the Transport Layer should include frame sequencing and acknowledgment, as well as retransmission of unacknowledged frames.
implemented in the transport driver
5． Session layer
Manages the connection between cooperating applications, including high-level synchronization and monitoring of which application is "talking" and which is "listening."
6． Presentation layer
Handles data formatting, including issues such as whether lines end in carriage return/line feed (CR/LF) or just carriage return (CR), whether data is to be compressed or encoded, and so forth.
7． Application layer
Handles information transfer between two network applications, including functions such as security checks, identification of the participating machines, and initiation of the data exchange.
2． Windows 2000 Networking Components
The mapping between OSI layers and networking components isn't precise, which is the reason that some components cross layers.
TDI transports, for example, frequently cross several boundaries. In fact, the bottom four layers of software are often referred to collectively as "the transport." Software components residing in the upper three layers are referred to as "users of the transport."
