GS-2724 User’s Guide
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H A P T E R
19
Policy Rule
This chapter shows you how to configure policy rules.
19.1 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.
19.1.1 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.
19.1.2 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.
The DSCP value determines the forwarding behavior, the PHB (Per-Hop Behavior), that each
packet gets across the DiffServ network. Based on the marking rule, different kinds of traffic
can be marked for different kinds of forwarding. Resources can then be allocated according to
the DSCP values and the configured policies.
DSCP (6 bits)
Unused (2 bits)
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Страница 7: ...Safety Warnings GS 2724 User s Guide 7 ...
Страница 8: ...Safety Warnings GS 2724 User s Guide 8 ...
Страница 22: ...Table of Contents GS 2724 User s Guide 22 ...
Страница 30: ...List of Tables GS 2724 User s Guide 30 ...
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Страница 36: ...Chapter 1 Getting to Know Your Switch GS 2724 User s Guide 36 ...
Страница 40: ...Chapter 2 Hardware Installation and Connection GS 2724 User s Guide 40 ...
Страница 46: ...Chapter 3 Hardware Overview GS 2724 User s Guide 46 ...
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Страница 58: ...Chapter 4 The Web Configurator GS 2724 User s Guide 58 ...
Страница 64: ...Chapter 5 Initial Setup Example GS 2724 User s Guide 64 ...
Страница 70: ...Chapter 6 System Status and Port Statistics GS 2724 User s Guide 70 ...
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Страница 94: ...Chapter 8 VLAN GS 2724 User s Guide 94 Figure 36 Port Based VLAN Setup All connected ...
Страница 126: ...Chapter 16 Port Authentication GS 2724 User s Guide 126 ...
Страница 130: ...Chapter 17 Port Security GS 2724 User s Guide 130 ...
Страница 136: ...Chapter 18 Classifier GS 2724 User s Guide 136 Figure 58 Classifier Example ...
Страница 139: ...Chapter 19 Policy Rule GS 2724 User s Guide 139 Figure 59 Policy ...
Страница 145: ...Chapter 20 Queuing Method GS 2724 User s Guide 145 ...
Страница 146: ...Chapter 20 Queuing Method GS 2724 User s Guide 146 ...
Страница 152: ...Chapter 21 VLAN Stacking GS 2724 User s Guide 152 ...
Страница 165: ...165 PART IV IP Application Static Route 167 RIP 169 IGMP 171 Differentiated Services 173 DHCP 177 ...
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Страница 183: ...Chapter 27 DHCP GS 2724 User s Guide 183 Figure 89 DHCP Relay Configuration Example ...
Страница 184: ...Chapter 27 DHCP GS 2724 User s Guide 184 ...
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Страница 210: ...Chapter 31 Syslog GS 2724 User s Guide 210 ...
Страница 224: ...Chapter 36 Routing Table GS 2724 User s Guide 224 ...
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Страница 262: ...Chapter 38 Introducing Commands GS 2724 User s Guide 262 ...
Страница 296: ...Chapter 42 IEEE 802 1Q Tagged VLAN Commands GS 2724 User s Guide 296 ...
Страница 300: ...Chapter 44 Routing Domain Command Examples GS 2724 User s Guide 300 ...
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Страница 312: ...Appendix B Changing a Fuse GS 2724 User s Guide 312 ...
Страница 332: ...Appendix E Common Services GS 2724 User s Guide 332 ...
Страница 336: ...Appendix F Legal Information GS 2724 User s Guide 336 ...
Страница 348: ...Index GS 2724 User s Guide 348 ...