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To configure the aforementioned DSCP and PFC priority values, perform the following tasks:
1. Create class-maps to group the DSCP subsets
class-map match-any dscp-pfc-1
match ip dscp 0-5,10-15
!
class-map match-any dscp-pfc-2
match ip dscp 20-25,30-35
2. Associate above class-maps to Queues Queue assignment as below.
NOTE: Although, each port on the S4810, S4820T, and S5000 devices support 8 QoS queues, you can configure only 4
QoS queues (0-3)to manage data traffic. The remaining 4 queues (4-7) are reserved for control traffic.
Table 18. Queue Assignments
Internal-
priority
0 1 2 3 4 5 6 7
Queue 0 0 0 1 2 3 3 3
Table 18. Queue Assignments
Internal-
priority
0 1 2 3 4 5 6 7
Queue 2 0 1 3 4 5 6 7
3. Dot1p->Queue Mapping Configuration is retained at the default value.
Default dot1p-queue mapping is,
DellEMC#show qos dot1p-queue-mapping
Dot1p Priority : 0 1 2 3 4 5 6 7
Queue : 0 0 0 1 2 3 3 3
Default dot1p-queue mapping is,
DellEMC#show qos dot1p-queue-mapping
Dot1p Priority : 0 1 2 3 4 5 6 7
Queue : 2 0 1 3 4 5 6 7
4. Interface Configurations on server connected ports.
a. Enable DCB globally.
DellEMC(conf)#dcb enable
b. Apply PFC Priority configuration. Configure priorities on which PFC is enabled.
DellEMC(conf-if-te-1/1)#pfc priority 1,2
Using PFC to Manage Converged Ethernet Traffic
To use PFC for managing converged Ethernet traffic, use the following command:
dcb-map stack-unit all dcb-map-name
Configure Enhanced Transmission Selection
ETS provides a way to optimize bandwidth allocation to outbound 802.1p classes of converged Ethernet traffic.
Different traffic types have different service needs. Using ETS, you can create groups within an 802.1p priority class to
configure different treatment for traffic with different bandwidth, latency, and best-effort needs.
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Data Center Bridging (DCB)