OSI 7 Layer Reference Model

OSI 7 Layer Reference Model

A reference model for communication protocols designed to allow open systems interconnection.

The seven layers are:

1. Physical
2. Data link
3. Network
4. Transport
5. Session
6. Presentation
7. Application

For more information see:

• www.erg.abdn.ac.uk/users/gorry/course/intro-pages/osi.html 
• www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/osi_prot.htm
• http://everything.explained.at/OSI_model - OSI 7 layer model explained.