Telkom duoPlus 300WR, Manual

Page: 76 / 127

duoPlus 300WR User Manual
Page 76 of 127
Quality of Service
Quality of service allows network administrators to configure routers to meet the real
time requirements for voice and video.
Different networks use different QoS markings like:
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ToS network: ToS bits in the IP header
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VLAN network: priority bits in the VLAN header
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DSCP network: uses only 5 bits of the CoS
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WLAN: WLAN QoS header.
The QoS framework is supported on all the above domains. How do you make them
talk to each other? How can you make sure the priority from one network is carried
over to another network? Class of service (CoS) is introduced as the common
language for the QoS mappings. When QoS is enabled, the router has full control
over packets from the time they enter the router till they leave the router. This is how
it works: The domain mapping (ToS bits, priority bits, etc.) of a packet needs to be
translated to CoS when the packet enter the router, and vice versa, the CoS of a
packet needs to be translated back to the domain mapping when the packet leaves
the router.
There are 6 types of CoS (in descending priority):
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CoS1
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CoS2
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CoS3
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CoS4
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CoS5
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CoS6