OSI layer

							So the computer can send information to another computer, and can
receive and understand information, there must be rules or standards for the process
the communication. This standard assures us that some types of products and
devices can communicate with other devices of different pass
some networks. Standardization of this standard is called "MODEL" ..

International Standards Organization (ISO) has created a model widely
for industry, or "framework", to define network rules
must be made for reliable communication. The network model is divided into
"Layer", which each layer has different functions in the process
of communication.

Benefits of Network Model

The network model is useful for the design, architecture and implementation of the
network,
include:

  1. Reduce complexity, the process of division within the group, ataulayer,
implementation becomes simpler network architecture.
  2. Provides compatibility, keseuaian standard interface for "plug-and-play" and
integration among multi-vendor.
  3. Modular facility - allows Removable "swap" of new technology at each layer and the
network architecture is maintained.
  4. Accelerate the evolution of technology, developers focus on one layer while keeping
the impact on other layers.
  5. Easy to learn - the division into the group process will reduce complexity and ease of
understanding.

OSI Network Model

Model Open Systems Interconnection (OSI) was created by the International
Organization for Standardization (ISO) which provides a framework of structured logic
how the process interacts data communication over a network.
Standards were developed for the computer industry can communicate on a different
network efficiently.

OSI Layer Model




There are seven layers in the OSI model. Each layer is responsible for a particular
the data communication process. For example, one layer may be responsible for
establishing connections between devices, while another layer is responsible
to correct the "errors" during the data transfer process takes place.

Layers of the OSI model is divided into two groups: "upper layer" and "lower layer".
"Upper layer" focus on user applications and how to file
represented in the computer. For Network Engineer, a major part of
became the focus is on "lower layer". Lower layer is the essence
actual data communication over a network.

7 layer OSI

  * Application Layer

   Provides services for user applications. This layer is responsible for the exchange of
information between computer programs, such as e-mail programs, and other service
roads in the network, such as a printer server or other computer applications.

  * Presentation Layer

  Responsible for how data is converted and formatted for data transfer.
  Example conversion of ASCII text format for documents,. Gif and JPG for images.
This layer performs code conversion, data translation, encryption and conversion.

  * Session Layer

  Determine how the two devices establish, maintain and manage a connection -
  how they relate to one samalain. These connections are called "session".

  * Transport Layer

   Responsible for dividing data into segments, logical connection "end-to-end" between
terminals, and provides error handling (error handling).

  * Network Layer

  Responsible for determining the network address, specify the route to be taken during
the trip, and keep the network traffic congestion. The data on this layer-shaped package.

  * Data Link Layer:

   Provides links to data, packaged into frames associated with the "hardware" and then
transported via media.komunikasinya with a network card, set the physical layer
communication connection between the system and error handling.

  * Physical Layer

  Responsible for the process of data into bits and transfer them through the media,
  such as cables, and maintain the physical connections between systems.


"Open" in the OSI

"Open" in the OSI network model is to declare that interconnect regardless of the
hardware / "Hardware" is used, all in accordance with standard communications software.
This indirectly led to "modularity" (can be dismantled pairs).

Modularity

"Modularity" refers to the exchange of protocol at a certain level without affecting or
damaging relationships or functions of other levels.

In a layer, protocol interchangeable, and enables communication
continue to take place. This exchange took place based on the hardware
"Hardware" from different vendors and a variety of reasons or a desire
are different.