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Chapter 49 Differentiated Services
XS3800-28 User’s Guide
357
C
HAPTER
49
Differentiated Services
49.1 DiffServ Overview
This chapter shows you how to configure Differentiated Services (DiffServ) on the Switch.
Quality of Service (QoS) is used to prioritize source-to-destination traffic flows. All packets in the flow are
given the same priority. You can use CoS (class of service) to give different priorities to different packet
types.
DiffServ 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.
49.1.1 What You Can Do
• Use the
Diffserv
screen (
) to activate DiffServ to apply marking rules or IEEE
802.1p priority mapping on the Switch.
• Use the
DSCP
Setting
screen (
) to change the DSCP-IEEE 802.1p mapping.
49.1.2 What You Need to Know
Read on for concepts on Differentiated Services that can help you configure the screens in this chapter.
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 6-bit DSCP field which can define up to 64 service levels and the
remaining 2 bits are defined as currently unused (CU). The following figure illustrates the DS field.
Figure 265
DiffServ: Differentiated Service 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 PHB (Per-Hop Behavior), that each packet gets as it is forwarded across
the DiffServ network. Based on the marking rule different kinds of traffic can be marked for different
DSCP (6 bits)
CU (2 bits)
Содержание XS3800-28
Страница 29: ...29 PART I User s Guide...
Страница 54: ...54 PART II Technical Reference...
Страница 88: ...Chapter 4 Web Configurator XS3800 28 User s Guide 88 Figure 51 Online Web Help...
Страница 123: ...Chapter 13 Neighbor XS3800 28 User s Guide 123 Figure 77 MONITOR Neighbor Neighbor Details Standalone Mode...
Страница 139: ...Chapter 17 System Information XS3800 28 User s Guide 139 Figure 90 MONITOR System Information Standalone Mode...
Страница 148: ...Chapter 20 Cloud Management XS3800 28 User s Guide 148 Figure 94 SYSTEM Cloud Management...
Страница 221: ...Chapter 33 Green Ethernet XS3800 28 User s Guide 221 Figure 149 PORT Green Ethernet Standalone Mode...
Страница 263: ...Chapter 36 OAM XS3800 28 User s Guide 263 Figure 182 PORT OAM OAM Status OAM Details...
Страница 334: ...Chapter 44 Multicast XS3800 28 User s Guide 334 Figure 248 MVR Group Configuration Example View...
Страница 406: ...Chapter 54 Spanning Tree Protocol XS3800 28 User s Guide 406 Figure 302 MSTP and Legacy RSTP Network Example...
Страница 420: ...Chapter 57 VLAN XS3800 28 User s Guide 420 Figure 315 SWITHCING VLAN VLAN Setup Static VLAN Add Edit Standalone Mode...
Страница 439: ...Chapter 57 VLAN XS3800 28 User s Guide 439 Figure 336 SWITCHING VLAN Port Based VLAN Setup Port Isolation...
Страница 540: ...Chapter 72 VRRP XS3800 28 User s Guide 540 Figure 434 VRRP Example 2 VRRP Status on Switch B...
Страница 581: ...Chapter 77 Policy Rule XS3800 28 User s Guide 581 Figure 456 Policy Example...
Страница 658: ...Chapter 86 Port Security XS3800 28 User s Guide 658 Figure 521 SECURITY Port Security Standalone Mode...
Страница 678: ...Chapter 87 MAINTENANCE XS3800 28 User s Guide 678 Figure 542 MAINTENANCE Configuration Configure Clone Stacking Mode...
Страница 680: ...Chapter 87 MAINTENANCE XS3800 28 User s Guide 680 Figure 543 MAINTENANCE Diagnostic Standalone Mode...
Страница 684: ...Chapter 87 MAINTENANCE XS3800 28 User s Guide 684 Figure 545 MAINTENANCE Firmware Upgrade Standalone Mode...
Страница 747: ...747 PART III Troubleshooting and Appendices...