The OpenSystemsInterconnect (OSI) model is a top-down analysis set. There are 7 (academically) distinct layers in the Model:
The most practical implementations of the ISO/OSI model have 4 layers, which merges some of the layers together, splitting them by logical distinctions.
Reference: http://www.scit.wlv.ac.uk/~jphb/comms/std.7layer.html
Also referred to as: Network Layering Principles, ISO/OSI model
The long and the short of it is that nobody believes in the OSI protocol stack. People believe in the TCP/IP protocol stack, but not OSI. Hell, the OSI model was only made packet-oriented at the last minute. -- rk
OSI model has succeeded if only it has served as a reference for start of debate on implementation aspects. Moreover, I have seen a lot of mapping of SecurityManagement material to this model -- dl
The real reference is the Unix implementation of TCP/IP. The OSI model isn't a reference for anything and the notion that it triggered debate of implementation is absurd. The OSI model wasn't made until long after TCP/IP was a resounding success. You've got your history backward.
By the way, the OSI model is sometimes referred to as "the seven layer salad."
Contributors: SusanRoy, MartySchrader