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Tech Note #22: Asynchronous Transfer Mode (ATM)  Addresses
1998 Bionic Buffalo Corporation; All Rights Reserved.
       14 September 1998
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ATM Network
User Plane
The top surface of the block is called the user plane, because it represents the network as seen
from the point of view of the user. For example, viewing a simple PVC from the user plane, it
may appear as follows:
User Plane
connection points
User 1
User 2
From the user plane, the network simply associates two connection points, allowing the user to
move messages between them. The details of how the connection is made are hidden from the
user. From the ATM network’s point of view, however, there are protocol stacks involved. If
the same connection is viewed from the side of the block, it looks like this: