2006-10-11 21:48:52 · 4 answers · asked by Anonymous in Computers & Internet ➔ Internet
Open System Interconnection(OSI) is an ISO standard for worldwide communications that defines a framework for implementing protocols in seven layers. Control is passed from one layer to the next, starting at the application layer in one station, proceeding to the bottom layer, over the channel to the next station and back up the hierarchy.The OSI serves as a reference model for all network protocols because its functionality exists in all communications systems.
There are 7 layers :
7 .Application layer
6 .Presentation layer
5 .Session layer
4 .Transport layer
3 .Network layer
2 .Data link layer
1 .Physical layer
Each layer has the property that it only uses the functions of the layer below, and only exports functionality to the layer above.This logical separation of layers makes reasoning about the behavior of protocol stacks much easier, allowing the design of elaborate but highly reliable protocol stacks.
2006-10-11 22:02:50 · answer #1 · answered by Y Raghavendra Reddy 2 · 1⤊ 0⤋
Interconnection, an ISO standard for worldwide communications that defines a networking framework for implementing protocols in seven layers. Control is passed from one layer to the next, starting at the application layer in one station, proceeding to the bottom layer, over the channel to the next station and back up the hierarchy.
At one time, most vendors agreed to support OSI in one form or another, but OSI was too loosely defined and proprietary standards were too entrenched. Except for the OSI-compliant X.400 and X.500 e-mail and directory standards, which are widely used, what was once thought to become the universal communications standard now serves as the teaching model for all other protocols.
Most of the functionality in the OSI model exists in all communications systems, although two or three OSI layers may be incorporated into one.
OSI is also referred to as the OSI Reference Model or just the OSI Model.
2006-10-11 21:53:43 · answer #2 · answered by Dhaval 2 · 1⤊ 0⤋
http://www.novell.com/info/primer/prim05.html
this will explain everything you need to know. See the image about mid-page.
2006-10-11 21:53:11 · answer #3 · answered by Big D 2 · 0⤊ 0⤋
it is logical parts of the compuer system
2006-10-11 21:51:38 · answer #4 · answered by debasis 3 · 0⤊ 0⤋