D-Link DES-3326SR User Manual page 81

DES-3326SR Layer 3 Fast Ethernet Switch User's Guide
Protocol layering as simply a tool for visualizing the
organization of the necessary software and hardware in a
network. In this view, Layer 2 represents switching and Layer
3 represents routing. Protocol layering is actually a set of
guidelines used in writing programs and designing hardware
that delegate network functions and allow the layers to
communicate. How these layers communicate within a stack
(for example, within a given computer) is left to the operating
system programmers.
Figure 5-9. The Protocol Stack
Between two protocol stacks, members of the same layer are
known as peers and communicate by well-known (open and
published) protocols. Within a protocol stack, adjacent
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