KOMMUNIKATSIYALARINI RIVOJLANTIRISH VAZIRLIGI
MUHAMMAD AL-XORAZMIY NOMIDAGI
TOSHKENT AXBOROT TEXNOLOGIYALARI UNIVERSITETI
Telekomunikatsiya fakulteti
Kompyuter tarmoqlari
Mustaqil Ish 1
Guruh: 041-21
Bajardi: Kenjayev M
Tekshirdi Matqurbonov D.
APPLICATION LAYER
The application layer in the OSI model is the closest layer to the end user which means that the application layer and end user can interact directly with the software application. The application layer programs are based on client and servers.
The Application layer includes the following functions:
Identifying communication partners: The application layer identifies the availability of communication partners for an application with data to transmit.
Determining resource availability: The application layer determines whether sufficient network resources are available for the requested communication.
Synchronizing communication: All the communications occur between the applications requires cooperation which is managed by an application layer.
Services
of Application Layers
Network Virtual terminal: An application layer allows a user to log on to a remote host. To do so, the application creates a software emulation of a terminal at the remote host. The user's computer talks to the software terminal, which in turn, talks to the host. The remote host thinks that it is communicating with one of its own terminals, so it allows the user to log on.
File Transfer, Access, and Management (FTAM): An application allows a user to access files in a remote computer, to retrieve files from a computer and to manage files in a remote computer. FTAM defines a hierarchical virtual file in terms of file structure, file attributes and the kind of operations performed on the files and their attributes.
Addressing: To obtain communication between client and server, there is a need for addressing. When a client made a request to the server, the request contains the server address and its own address. The server response to the client request, the request contains the destination address, i.e., client address. To achieve this kind of addressing, DNS is used.
