Table B-1. Seven-Layer Osi Model - ADTRAN Atlas 550 User Manual

Appendix B
OSI MODEL
Layer Title
Layer 7 Application
Layer 6 Presentation Provides transparent communication by creating code and syntax
Layer 5 Session
Layer 4 Transport
Layer 3 Network
Layer 2 Data Link
Layer 1 Physical
61200305L1-1
OSI Model and Frame Relay
Technology Overview
This chapter discusses the OSI Model, Frame Relay Protocol, and Transpar-
ent Bit Oriented Protocol (TBOP).
The Open Systems Interconnection (OSI) model is an internationally accept-
ed standard for communication between multiple vendors' communication
equipment. It relies on a seven-layer model to allow communication be-
tween communication equipment. Table B-1 describes these layers.
Contains functions for end-user services. These include FTP , remote file
access, and network management. This is not the application, but the
interface.
compatibility between systems.
Takes care of the communication facility provided by the transport layer
(layer 4). Allows sessions to be established, recovered, and terminated.
Provides some error correction and end-to-end flow control. Also decides
best route for the information being transmitted.
Determines the method for transmitting data and also deals with routing
the data between networks. Moves data based on addressing.
Deals with procedures and protocols for controlling the transmission line.
Provides some error detection and correction.
Deals with the electrical, mechanical, and functional control of sending
data over the transmission lines.
By defining standard interfaces between each of the seven layers, an individ-
ual layer only has to know about the interface to the layer above, to the layer
below, and to the same layer on the other end of the network. This interface
definition simplifies the process of networking.
ATLAS 550 User Manual

Table B-1. Seven-Layer OSI Model

Description
B-1