184 lines
3.4 KiB
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184 lines
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>14.2. Clark-Shenker-Zhang algorithm (CSZ)</H1
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><P
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>This is so theoretical that not even Alexey (the main CBQ author) claims to
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understand it. From his source:</P
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>David D. Clark, Scott Shenker and Lixia Zhang
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<I
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CLASS="CITETITLE"
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>Supporting Real-Time Applications in an Integrated Services Packet
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Network: Architecture and Mechanism</I
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>.</P
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>As I understand it, the main idea is to create WFQ flows for each guaranteed
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service and to allocate the rest of bandwith to dummy flow-0. Flow-0
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comprises the predictive services and the best effort traffic; it is handled
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by a priority scheduler with the highest priority band allocated for
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predictive services, and the rest --- to the best effort packets.</P
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><P
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>Note that in CSZ flows are NOT limited to their bandwidth. It is supposed
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that the flow passed admission control at the edge of the QoS network and it
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doesn't need further shaping. Any attempt to improve the flow or to shape it
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to a token bucket at intermediate hops will introduce undesired delays and
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raise jitter.</P
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><P
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>At the moment CSZ is the only scheduler that provides true guaranteed
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service. Another schemes (including CBQ) do not provide guaranteed delay and
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randomize jitter."</P
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>Does not currently seem like a good candidate to use, unless you've read and
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understand the article mentioned.</P
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