AT-S63 Management Software Features Guide
Section II: Advanced Operations
167
DiffServ Domains
Differentiated Services (DiffServ) is a method of dividing IP traffic into
classes of service, without requiring that every router in a network
remember detailed information about traffic flows. DiffServ operates within
a
DiffServ domain
, a network or subnet that is managed as a single QoS
unit. Packets are classified according to user-specified criteria at the edge
of the network, divided into classes, and assigned the required class of
service. Then packets are marked with a Differentiated Services Code
Point (DSCP) tag to indicate the class of service to which they belong. The
DSCP value is written into the TOS field of the IP header. Routers within
the network then use this DSCP value to classify packets and assign QoS
appropriately. When a packet leaves the DiffServ domain, the DSCP value
can be replaced with a value appropriate for the next DiffServ domain.
A simple example of this process is shown in Figure 13, for limiting the
amount of bandwidth used by traffic from a particular IP address. In the
domain shown, this bandwidth limit is supplied by the class of service
represented by a DSCP value of 40. In the next DiffServ domain, this
traffic is assigned to the class of service represented by a DSCP value of
3.
Figure 13. DiffServ Domain Example
Non-DiffServ
traffic
Classify by source IP address
Mark with DSCP=40
Limit bandwidth
DiffServ Domain
Classify by DSCP=40
Limit bandwidth
Classify by DSCP=40
Limit bandwidth
Re-mark to DSCP=3
Next DiffServ
domain
Содержание AT-S63
Страница 14: ...Figures 14 ...
Страница 18: ...Tables 18 ...
Страница 28: ...28 Section I Basic Operations ...
Страница 58: ...Chapter 1 Overview 58 ...
Страница 76: ...Chapter 2 AT 9400Ts Stacks 76 Section I Basic Operations ...
Страница 96: ...Chapter 5 MAC Address Table 96 Section I Basic Operations ...
Страница 114: ...Chapter 8 Port Mirror 114 Section I Basic Operations ...
Страница 116: ...116 Section II Advanced Operations ...
Страница 146: ...Chapter 12 Access Control Lists 146 Section II Advanced Operations ...
Страница 176: ...Chapter 14 Quality of Service 176 Section II Advanced Operations ...
Страница 196: ...196 Section III Snooping Protocols ...
Страница 204: ...Chapter 18 Multicast Listener Discovery Snooping 204 Section III Snooping Protocols ...
Страница 216: ...Chapter 20 Ethernet Protection Switching Ring Snooping 216 Section III Snooping Protocols ...
Страница 218: ...218 Section IV SNMPv3 ...
Страница 234: ...234 Section V Spanning Tree Protocols ...
Страница 268: ...268 Section VI Virtual LANs ...
Страница 306: ...Chapter 27 Protected Ports VLANs 306 Section VI Virtual LANs ...
Страница 320: ...320 Section VII Internet Protocol Routing ...
Страница 360: ...Chapter 30 BOOTP Relay Agent 360 Section VII Routing ...
Страница 370: ...Chapter 31 Virtual Router Redundancy Protocol 370 Section VII Routing ...
Страница 372: ...372 Section VIII Port Security ...
Страница 402: ...Chapter 33 802 1x Port based Network Access Control 402 Section VIII Port Security ...
Страница 404: ...404 Section IX Management Security ...
Страница 436: ...Chapter 36 PKI Certificates and SSL 436 Section IX Management Security ...
Страница 454: ...Chapter 38 TACACS and RADIUS Protocols 454 Section IX Management Security ...
Страница 462: ...Chapter 39 Management Access Control List 462 Section IX Management Security ...
Страница 504: ...Appendix B SNMPv3 Configuration Examples 504 Security Model Security Level Storage Type SNMPv3 Parameters Continued ...
Страница 532: ...Appendix D MIB Objects 532 ...