Quick Reference Guide

408 PowerConnect B-Series TI24X Configuration Guide
53-1002269-02
QoS queues
15
Mapping between DSCP value and Forwarding Queue cannot be changed. However, mapping
between DSCP values and the other properties can be changed as follows:
• DSCP to internal forwarding priority mapping – You can change the mapping between the
DSCP value and the Internal Forwarding priority value from the default values shown in
Table 58 through Table 61. This mapping is used for COS marking and determining the internal
priority when the trust level is DSCP. Refer to “Changing the DSCP –> internal forwarding
priority mappings” on page 412.
• Internal forwarding priority to forwarding queue – You can reassign an internal forwarding
priority to a different hardware forwarding queue. Refer to “Changing the internal forwarding
priority –> hardware forwarding queue mappings” on page 413.
QoS queues
Devices support the eight QoS queues (qosp0 – qosp7) listed in Table 62.
The queue names listed above are the default names. If desired, you can rename the queues as
instructed in “Renaming the queues” on page 416.
Packets are classified and assigned to specific queues based on the criteria shown in Figure 82.
Assigning QoS priorities to traffic
By default, all traffic is in the best-effort queue (qosp0) and is honored on tagged ports on all
PowerConnect switches. You can assign traffic to a higher queue based on the following:
• Incoming port (sometimes called the ingress port)
• Static MAC entry
Internal
Forwarding
Priority
6666666677777777
Forwarding
Queue
6666666677777777
TABLE 61 Default QoS mappings, columns 48 to 63 (Continued)
DSCP value 48495051525354555657585960616263
TABLE 62 QoS queues
QoS Priority Level QoS Queue
0 qosp0 (lowest priority queue)
1qosp1
2qosp2
3qosp3
4qosp4
5qosp5
6qosp6
7 qosp7 (highest priority queue)