Chapter 10 Quality of Service (QoS)
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10.2 What You Need to Know
The following terms and concepts may help as you read through this chapter.
QoS versus Cos
QoS is used to prioritize source-to-destination traffic flows. All packets in the same flow are given
the same priority. CoS (class of service) is a way of managing traffic in a network by grouping
similar types of traffic together and treating each type as a class. You can use CoS to give different
priorities to different packet types.
CoS technologies include IEEE 802.1p layer 2 tagging and DiffServ (Differentiated Services or DS).
IEEE 802.1p tagging makes use of three bits in the packet header, while DiffServ is a new protocol
and defines a new DS field, which replaces the eight-bit ToS (Type of Service) field in the IP header.
Tagging and Marking
In a QoS class, you can configure whether to add or change the DSCP (DiffServ Code Point) value,
IEEE 802.1p priority level and VLAN ID number in a matched packet. When the packet passes
through a compatible network, the networking device, such as a backbone switch, can provide
specific treatment or service based on the tag or marker.
Traffic Shaping
Bursty traffic may cause network congestion. Traffic shaping regulates packets to be transmitted
with a pre-configured data transmission rate using buffers (or queues). Your Device uses the Token
Bucket algorithm to allow a certain amount of large bursts while keeping a limit at the average rate.
Tr
af
fi
c
Time
Traffic Rate
Tr
af
fi
c
Time
Traffic Rate
(Before Traffic Shaping)
(After Traffic Shaping)
Summary of Contents for VWG1312-B10A
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Page 8: ...Contents Overview VMG1312 B10A User s Guide 8 Troubleshooting 291 ...
Page 18: ...Table of Contents VMG1312 B10A User s Guide 18 ...
Page 19: ...19 PART I User s Guide ...
Page 20: ...20 ...
Page 34: ...Chapter 2 The Web Configurator VMG1312 B10A User s Guide 34 ...
Page 39: ...Chapter 4 Tutorials VMG1312 B10A User s Guide 39 7 Click Apply to save your settings ...
Page 79: ...79 PART II Technical Reference ...
Page 80: ...80 ...
Page 168: ...Chapter 9 Routing VMG1312 B10A User s Guide 168 ...
Page 186: ...Chapter 10 Quality of Service QoS VMG1312 B10A User s Guide 186 ...
Page 212: ...Chapter 13 Interface Group VMG1312 B10A User s Guide 212 ...
Page 228: ...Chapter 15 Firewall VMG1312 B10A User s Guide 228 ...
Page 234: ...Chapter 17 Parental Control VMG1312 B10A User s Guide 234 ...
Page 244: ...Chapter 19 Certificates VMG1312 B10A User s Guide 244 ...
Page 248: ...Chapter 20 Log VMG1312 B10A User s Guide 248 ...
Page 252: ...Chapter 21 Traffic Status VMG1312 B10A User s Guide 252 ...
Page 258: ...Chapter 24 IGMP Status VMG1312 B10A User s Guide 258 ...
Page 262: ...Chapter 25 xDSL Statistics VMG1312 B10A User s Guide 262 ...
Page 264: ...Chapter 26 User Account VMG1312 B10A User s Guide 264 ...
Page 270: ...Chapter 29 TR 064 VMG1312 B10A User s Guide 270 ...
Page 274: ...Chapter 30 Time Settings VMG1312 B10A User s Guide 274 ...
Page 280: ...Chapter 32 Logs Setting VMG1312 B10A User s Guide 280 ...
Page 298: ...Chapter 36 Troubleshooting VMG1312 B10A User s Guide 298 ...
Page 338: ...Appendix C Pop up Windows JavaScripts and Java Permissions VMG1312 B10A User s Guide 338 ...
Page 352: ...Appendix D Wireless LANs VMG1312 B10A User s Guide 352 ...
Page 368: ...Appendix G Legal Information VMG1312 B10A User s Guide 368 ...
Page 376: ...VMG1312 B10A User s Guide 376 Index ...