XGS-4728F User’s Guide
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Policy Rule
This chapter shows you how to configure policy rules.
21.1 Policy Rules Overview
A classifier distinguishes traffic into flows based on the configured criteria (refer to
for more information). A policy rule ensures that a traffic
flow gets the requested treatment in the network.
21.1.1 DiffServ
DiffServ (Differentiated Services) is a class of service (CoS) model that marks
packets so that they receive specific per-hop treatment at DiffServ-compliant
network devices along the route based on the application types and traffic flow.
Packets are marked with DiffServ Code Points (DSCPs) indicating the level of
service desired. This allows the intermediary DiffServ-compliant network devices
to handle the packets differently depending on the code points without the need to
negotiate paths or remember state information for every flow. In addition,
applications do not have to request a particular service or give advanced notice of
where the traffic is going.
21.1.2 DSCP and Per-Hop Behavior
DiffServ defines a new DS (Differentiated Services) field to replace the Type of
Service (TOS) field in the IP header. The DS field contains a 2-bit unused field and
a 6-bit DSCP field which can define up to 64 service levels. The following figure
illustrates the DS field.
DSCP is backward compatible with the three precedence bits in the ToS octet so
that non-DiffServ compliant, ToS-enabled network device will not conflict with the
DSCP mapping.
DSCP (6 bits)
Unused (2 bits)
Summary of Contents for XGS-4728F
Page 2: ......
Page 8: ...Safety Warnings XGS 4728F User s Guide 8 ...
Page 24: ...24 ...
Page 30: ...Chapter 1 Getting to Know Your Switch XGS 4728F User s Guide 30 ...
Page 34: ...Chapter 2 Hardware Installation and Connection XGS 4728F User s Guide 34 ...
Page 42: ...Chapter 3 Hardware Overview XGS 4728F User s Guide 42 ...
Page 44: ...44 ...
Page 78: ...Chapter 7 System Status and Port Statistics XGS 4728F User s Guide 78 ...
Page 92: ...Chapter 8 Basic Setting XGS 4728F User s Guide 92 ...
Page 94: ...94 ...
Page 114: ...Chapter 9 VLAN XGS 4728F User s Guide 114 ...
Page 118: ...Chapter 10 Static MAC Forward Setup XGS 4728F User s Guide 118 ...
Page 148: ...Chapter 14 Bandwidth Control XGS 4728F User s Guide 148 ...
Page 162: ...Chapter 17 Link Aggregation XGS 4728F User s Guide 162 ...
Page 186: ...Chapter 21 Policy Rule XGS 4728F User s Guide 186 ...
Page 230: ...Chapter 25 AAA XGS 4728F User s Guide 230 ...
Page 268: ...268 ...
Page 324: ...324 ...
Page 332: ...Chapter 38 Maintenance XGS 4728F User s Guide 332 ...
Page 358: ...Chapter 41 Syslog XGS 4728F User s Guide 358 ...
Page 366: ...Chapter 42 Cluster Management XGS 4728F User s Guide 366 ...
Page 370: ...Chapter 43 MAC Table XGS 4728F User s Guide 370 ...
Page 374: ...Chapter 44 IP Table XGS 4728F User s Guide 374 ...
Page 378: ...Chapter 46 Routing Table XGS 4728F User s Guide 378 ...
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Page 392: ...Chapter 48 Troubleshooting XGS 4728F User s Guide 392 ...
Page 402: ...Chapter 49 Product Specifications XGS 4728F User s Guide 402 ...
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Page 408: ...Appendix A Legal Information XGS 4728F User s Guide 408 ...