ATM Subsystem Traffic Management
The 3Com ONcore ATM subsystem supports the ATM Reserved Bandwidth (RB) service type of traffic.
In theReserved Bandwidth (RB) service, an application needs to establish a traffic contract with the network before transmitting data. The traffic contract consists of a
specified QOS class and a set | of traffic descriptors. Through resource allocation, the | ||||||||||||||||||
network | either | provides | the | desired | QOS | for | the | ATM connection | or | refuses | the call. |
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For this method, | the | source | must | be | accurately | modelled | and | able | to | precisely | descri | ||||||||
its traffic pattern. The allocated bandwidth | is usually less than the | peak | rate | in | ord | ||||||||||||||
benefit from statistical multiplexing gains which may cause | congestion. A | source |
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policing scheme ensures that the | source | conforms | itself | to | the contract by | means | of | a | |||||||||||
"leaky | bucket" | rate | control. |
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The use of selective and global | backpressure | for traffic | management in | the | ATM |
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subsystem gives the 3Com ONcore | ATM network an | addedSelective value. |
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backpressure | temporarily | stops | one | virtual | Globalconnectionbackpressure. |
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temporarily stops | an | ATM | link. |
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