1. INTRODUCTION
Network [1] is an important milestone in the development
of ISO (Internet Standard Organization, ISO) on the OSI
(Open System Interconnect) seven layer network model
definitions. It not only before and follow-up evaluation of
various network technologies, analysis of the basis, has
become the network protocol design and unified reference
model.
OSI (Open System Interconnection) is the Open Systems
Interconnection Reference Model [2] ISO International
Standards Organization[3] as defined by the OSI model
defines seven layers of function and it is a stepping stone for
beginners network technology, but also analysis, evaluation
based on a variety of network technologies - from the
network is no longer mysterious, it is rational Follow, are
based on evidence of.
OSI seven layer network model is mainly to address the
heterogeneous network interconnection compatibility issues
encountered when. Its biggest advantage is that services,
interfaces and protocols that a clear distinction between three
concepts; reduce the complexity of the issues, once the
network failure, which can quickly locate the fault level,
easy to find and error; service description of a layer What is
the upper layer to provide some functionality, the interface
shows how to use the lower layer of the service, and
agreements on how to achieve this level of service; This has
a strong independence between the layers, the
interconnection network entities what kind of agreement is
no limit, as long as up to provide the same services and the
interface does not change the adjacent layers on it. Seven of
the division of the network but also to the different functions