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