OSI Layers and Their Functions

Application layer
1. interface between the communications software and any applications
  1. It also defines processes for user authentication.
Presentation layer
1. define and negotiate data formats
  1. Encryption is also defined.
Session layer
1. how to start, control, and end conversations (called sessions).
  1. includes the control and management of multiple bidirectional messages
Transport layer
1. focuses on issues related to data delivery to another computer
  1. for example, error recovery and flow control
Network layer
1. Logical addressing
  1. defines how each device can have an address that can be used by the routing process
2. Routing
  1. defines how devices (typically routers) forward packets to their final destination
3. Path determination
  1. work done by routing protocols to learn all possible routes and choose the best route
Data link layer
1. defines the rules that determine when a device can send data over a particular medium
  1. also define the format of a header and trailer
Physical layer
1. refers to standards from other organizations
  1. These standards deal with the physical characteristics of the transmission medium

Resource summary

	Created by jce299792458 almost 12 years ago