Introduction
1–4
Fragment–Free Cut–Through Switching
This method of switching is a more conservative approach to cut–through switching by
waiting until the collision window has elapsed (that is, the first full 64 bytes have been
received) before processing the packet. This guarantees that the collision window for the
incoming frame has elapsed and that the frame will not be jammed by other stations. When
there are many stations on a segment, this method can significantly improve the utilization
of network bandwidth.
Store–and–Forward Switching
Traditional bridges and routers use a safe mode of switching called store–and–forward in
which the entire frame must be received before the bridge can perform a table lookup for
the destination node and forward the packet to the corresponding port. As a result, each
packet is delayed by approximately 800 microseconds. It may be necessary to use this
method of switching when many data errors are occurring over the network, or when
connecting to very slow devices.
Adaptive Cut–Through Switching
To ensure that you can manage any kind of network load, the DEL8X uses this method of
switching based on its smart algorithm. Adaptive cut–through switching dynamically
changes the way it handles data passing through the DEL8X based on the current CRC
error rate. These switching alternatives start with standard cut–through switching for a
clean data environment, change to fragment–free cut–through switching for a moderate
error rate, then progress to store–and–forward switching for a highly contentious
environment. By using this method, the DEL8X delivers the best networking performance
under any environment.
Features
The main features of the DEL8X are as follows:
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Eight independent 8–pin MJ 10 Mb/s or 100 Mb/s Ethernet ports
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Port 8 consists of one crossover–wired (x) port for connecting to PCs,
workstations, servers, bridges, and routers or one straight–wired port (//) for a
cascaded connection to another switch or compatible hub, thereby eliminating
the need for crossover cables
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Autosenses transmission speed (10/100 Mb/s)
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Autonegotiates transmission mode (half– or full–duplex) if supported by the
attached device
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Supports both full–duplex and half–duplex operation for all ports
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Total bandwidth of up to 1.6 Gb/s