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ATM switching unit

ATM switching units are exchanges ofATM cells. Since these have a constant size, a parallel architecture is used in the ATM switches, which enables throughput rates in the giga and terabit range and thus creates the prerequisites for high-speed networks such as B-ISDN.

The switching speeds in ATM switching units exceed the transmission rates of the connected stations many times over; for example, today's ATM switching units process 10 Gbit/s and more. In addition, all connected user channels can be processed simultaneously and in full.

Principle of the AT

Principle of the AT

M switch The ATM switching units identify the channel and path information and handle the cell transport from an input port of the switching network to an output port.

Scalability of the AT

Scalability of the AT

M switch A distinction is made between ATM switching units for path switching (VP switches, crossconnect) and channel switching (VC switches, ATM switches). In path switching, the incoming paths are terminated and redirected to another outgoing path. The channels remain unaffected.

ATM channel switching terminates both incoming paths and incoming channels and redirects them to outgoing paths or channels.

VPs and VCs in the switching node

VPs and VCs in the switching node

The actual transport of the ATM cells within the ATM switching unit takes place via the so-called switching fabric, the switching network. In principle, a switching unit can already be used as a switching fabric. Normally, however, the number of input or output ports is too small to meet the requirements placed on an ATM switching unit. Therefore, the switching elements are designed in a matrix structure or as TDM networks.

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Englisch: ATM switching unit
Updated at: 24.09.2007
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