tailieunhanh - Stuff - The OSI Model

Responsible for program to program communication • Provides services directly to applications, such as electronic mail, file transfer and terminal emulation • Responsible for identifying and establishing the availability of the intended partner and required resources • Responsible for determining if sufficient communication resources exist to reach the remote partner | 0 The 7 Layers of the OSI Model 7 7 Application 6 Presentation 6 5 4 Network Processes to Applications Provides network services to application processes such as electronic mail file transfer and terminal emulation 5 Session 3 2 4 Transport 3 1 Network 2 Data Link Responsible for program to program communication Provides services directly to applications such as electronic mail file transfer and terminal emulation Responsible for identifying and establishing the availability of the intended partner and required resources Responsible for determining if sufficient communication resources exist to reach the remote partner 0 The 7 Layers of the OSI Model 7 6 5 2 Network Processes to Applications Data Representation Insure data is readable by receiving system Format of data Data structures Negotiates data transfer syntax for application layer 1 Manages data presentation conversions. . Converting from EBCDIC to ASCII. Data encryption decryption compression and decompression Does this by using Abstract Syntax Notation 1 standardisation allows differing computer architectures to exchange data that are from differing computer architectures. Responsible for establishing and maintaining communications channels. In practice often combined with the Transport Layer. Facilitates a dialogue between communicating systems and controls the dialogue Simplex Half-duplex Full duplex Session set up by connection establishment data transfer and connection .