The OSI model

The international standard for Open Systems Interconnection (OSI) is defined by the document

ISO/IEC 7498-1, as outlined by the international standard organization and te international electrotechnical commision.the full standart is availabel as publication = ISOIEC 7498-1:1994.

The OSI model divides network traffic into a number of layer,

Each layer is independent of the layer around it,and each builds on the services provided by the layer below while providing new service to the layer above.the abstraction between layers makes it easy to disaign elaborate and highly realiable protocol stacks,such as the ubiquitous TCP/IPS stack.a protocol stack is an actual implementation of a layered communications framework.the OSI model doesn't define the protocol to be used in a particural network,but simply delegates each communications"job" to single layer whithin a welldefined hierarchy.while the ISO/IEC 7498-1 specification details how layers should interact with each other,it leaves the actual implementation details up to the manufacturer.earc layer can be implementation in hardware(moe common for lowe layers) or software.as long as the interface between layers adheres to the standard,implementers are free to use whatever means are available to built their protocol stack.this means that any given layer form manufacturer A can operate with the same layer form manufacturer B[assuming the relevant specifications are implemented and interpreted correctly.