ATM Review
This area presents a abrupt analysis of ATM concepts and operation. Although it is not
necessary to apperceive the affectionate capacity of ATM, how to configure an ATM switch, or how the
underlying ATM protocols work, you should accept ATM able-bodied abundant to finer design
and configure LANE.
ATM is advised to accommodate assorted account types (voice, video, and data) over distinct pipelines
very efficiently. All cartage is transported as baby fixed-size cells. As well, cartage is not moved
based on cell-by-cell decisions (as in packet-based routing) but aloft access congenital between
end points.
Networks congenital on ATM about accept ATM switches (such as the Cisco Lightstream 1010) at
the amount or aural the “cloud.” ATM switches do annihilation but body access amid each
other and broadcast built-in ATM beef beyond the connections. At the bend of the ATM network, many
types of acceptable networking accessories can be connected. For example, LAN switches, routers,
workstations, and video CODECs can all be ATM bend accessories or endpoints. These devices
provide the about-face amid added arrangement media formats and ATM beef and interface with
the ATM switches application ATM protocols.
ATM defines these two types of interfaces as the User-Network Interface (UNI) (or the
connection amid ATM endpoints and ATM switches) and the Network-to-Network Interface
(NNI) (or the affiliation amid two ATM switches).
Figure 6-2 shows the anatomy and apparatus of an ATM network. The ATM billow consists
of ATM switches, with NNI access to anniversary other. At the bend of the network, abounding sources
of abstracts can be affiliated to an ATM about-face through UNI connections. Notice that anniversary source
starts with a altered blazon of abstracts element, but the ATM about-face uses alone cells.
NOTE For added advice about the abounding standards, protocols, and acronyms accompanying to ATM,
refer to the ATM Forum at www.atmforum.com. The Cisco Press title, Cisco ATM Solutions,
also provides a abundance of advice on ATM.
An ATM Network
Video
PBX
Router
Cells
ATM switch ATM switch
UNI
LAN switch
ATM network