Home | Web Design | Programming | Fairlight CMI | Soap Box | Downloads | Links | Biography | About... | Site Map |
The ISO Open Systems Interconnection Model |
CA-Clipper | Opportunities | Tips and Tricks | Networking | Internal Errors | Source Code | CA-VO |
BACK TO CA-CLIPPER NETWORKING |
Each layer has a defined interface with the layer above and the layer below. This interface is made flexible so that designers can implement various communication protocols and still follow the standard. All of the major network operating systems conform to the ISO/OSI model. Layer 1: Physical This layer defines the physical connection between the computer and the network, including the mechanical aspects of the connection (cables and connectors) and the electrical aspects (voltage, current levels, and the techniques used to modulate the signal). This layer also defines the network's topology. Layer 2: Data Link This layer defines the protocol that computers must follow to access the network for transmitting and receiving messages. These messages are sent onto the network as specially formatted discrete frames of information rather than being continuously broadcast. If data input to this layer is large enough, the data-link layer will break it up into several frames. This layer also specifies handling of frame-receipt acknowledge (if required). |
Layer 3: Network
This layer defines how packets -- communications composed of a defined format of data frames -- are routed and relayed between networks. It also regulates packet flow and defines how status messages are sent to computers on the network. Layer 4: Transport The transport layer defines how you address the physical locations/devices on the network, how connection between nodes can be made and un-made, what the protocol is for guaranteed message delivery, and how to handle the inter-network routing of messages. Layer 5: Session This layer functions as the conceptual interface to the transport layer for applications. For example, it is this layer that lets you refer to devices by name rather than by their network address. This lets you write software that will run on any given installation of a given kind of network. Layer 6: Presentation This layer defines how applications can enter the network, and it translates the format and syntax of the data they produce and consume for it's transmission on the network. Layer 7: Application This uppermost layer simply defines the network applications that support file serving. Conceptually, this is where electronic mail and other network utility software exists. |
Home | Web Design | Programming | Fairlight CMI | Soap Box | Downloads | Links | Biography | About... | Site Map |
Send comments about this site to Greg at
gregh@ghservices.com All pages copyright © 1996-1999 GH Services Created 1997/06/09 Last updated 1999/09/30 All trademarks contained herein are the property of their respective owners |