| Variable
bit rate (VBR) |
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| RT-VBR:
Specified by the ATM Forum for services with |
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| stringent
timing requirements (”real-time applications”), |
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| like CBR but
for variable bit rate services, e.g. |
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| compressed
speech. |
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| NRT-VBR:
Specified by the ATM Forum for variable bit |
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| rate services
without stringent timing requirements |
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| (”non-real-time
applications”). |
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| In both VBR
service categories, we need to specify the |
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| following
traffic parameters: |
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| - Peak Cell Rate (PCR) |
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| - Sustainable Cell Rate (SCR) |
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| - Maximum Burst Size (MBS) |
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