Cajun P220G, Руководство по конфигурации и эксплуатации

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Overview of the P220G Gigabit Switch
Cajun P220G Switch Configuration and Operation Guide 1-7
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Adding gigabit speeds to existing networks means that there can be a huge disparity
between link speeds. For example, anything more than a 1-percent load on a gigabit link
could easily overwhelm a 10 Mb/s Ethernet link.
Without queue and buffer management, gigabit links might only move congestion in a
network, rather than relieving it.
The switch employs the following buffer and queue management techniques:
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Configurable active backpressure:
• Half-duplex ports use active backpressure to jam input ports when their frame
buffers are full.
• Full-duplex links use IEEE 802.3x pause control frames to pause traffic when
buffers are full.
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Packed frame buffers for optimal memory utilization. The P220G switch approach
to memory management allows virtually 100% utilization of buffer memory.
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Two Class of Service priority queues that provide flexible queue management
algorithms to meet application requirements.
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Large buffer space:
• 512KB per gigabit port or 10/100 ports
• 128KB additional for outbound 10/100 ports.
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Configurable queue depth for each of two prioritized packet queues.
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Configurable priority threshold.
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Configurable service ratio tunes queue priority.