Cabletron Systems STS16-20D 用户手册

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页码 258
19
Switch Overview
SmartStack STS16-20D/STS16-20R Token Ring Switches Installation and User Guide
The increase in throughput is directly proportional to the number of physical token-
rings that are interconnected through the switch. A SmartStack STS16-20D/
STS16-20R with 20 ports interconnected provides up to ten concurrent paths. With 
ten simultaneous conversations, the SmartStack STS16-20D/STS16-20R creates 
160 Mbps throughput in half-duplex mode, or 320 Mbps throughput in full-duplex 
mode.
A single segment can be dedicated to a single host or shared by several. To optimize 
throughput, high-speed servers can be given dedicated SmartStack STS16-20D/
STS16-20R ports.
By transporting multiple Token Ring packets simultaneously, it boosts overall 
network throughput.
Low Latency
When operating in cut-through mode, the SmartStack STS16-20D/STS16-20R 
minimizes latency—the time it takes to forward a packet from one Token Ring 
segment to another—by beginning switching immediately after looking at the first 
six bytes of the destination address in the packet. If the packet needs to be switched 
to another LAN segment, its data begins flowing through the destination port before 
the entire packet has been received. The result: packets can appear at the output port 
35 microseconds after entering the input port. Network devices that use store-and-
forward technology introduce much longer delays because they wait to receive the 
entire packet before forwarding it.
By minimizing delay, the SmartStack STS16-20D/STS16-20R can move more 
packets freely throughout the LAN without degrading performance.