Protocol Types
There are many protocols in use today, some protocols to meet international standards and there is only applicable to a particular computer. Therefore a lot of these protocol differences. To make the similarity of each protocol function, then there is an international agency set the standard communication protocol, this body is known as ISO (International Standards Organization). ISO makes standards called the OSI protocol (Open Systems Interconnections) and some companies also make other types of standard protocol among others:
OSI Model
This communication protocol has several levels that define a function and every level of its own. Level (Layer) according to the OSI protocol consists of:
- Application Layer
Which is the level where there is an application program of each user.
- Presentation Layer
This layer is the manipulation and process conversation data structure.
- Session Layer
Regulate coordination and synchronization conversation.
- Transport Layer
Set the transfer data from one system to another via transmission media.
- Network Layer
Here the route set of data flow in a computer communications network.
- Data Link Layer
arrange the data so that the error as small as possible (Error Recovery)
- Physical Layer
An existing communications equipment, such as cables, modems and other repeater.
OSI protocol examples are artificial HLDC (High Level Data Link Control) protocol layer is variations between each other but have similar functions, there may be reduced because the layer is governed by other layer. Layer standards issued by the OSI making computer vendors to design software for the communication protocol in accordance with the requirements.
Model DPA
This model was created by the U.S. defense agencies, to simplify the existing OSI model to meet criteria for American defense communications systems. DPA protocol using the principle of hierarchy which is not present in this model because it will be adjusted with the use of military methods commands principle, this protocol which uses a common communication method of access to the Network Host. This concept of the layer was formed consisting of 4 layers namely:
- 1. Network Access Layer
This layer served: Define Route Data, Control flow between the Host.
- 2. Internet Layer
This layer served to set Procedure accordance with existing network.
- 3. Host Layer
Set the Delivery of data between hosts.
- 4. Process / Application Layer
Setting the process data exchange applications.
