This protocol runs over the standard 802.2 data-link protocol layer. It is software that resides either in a computer s memory or in the memory of a transmission device, like a network interface card. When data is ready for transmission, this software is executed. The software prepares data for transmission and sets the transmission in motion. At the receiving end, the software takes the data off the wire and prepares it for the computer by taking off all the information added by the transmitting end.
Interfaces define how information is passed between adjacent layers in a given computer.
A layer is also referred to as 'Entity'. Looking vertically at the layers, we distinguish Service Users and Service Providers. Looking at the model horizontally, we can distinguish Entities that are at the same layer - these are called Peer Entities. All rights reserved.