Cabletron Systems STS16-20R - Manual (Page 33)

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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.