Configuration Example For Dscp And Pfc Priorities; Using Pfc To Manage Converged Ethernet Traffic; Generation Of Pfc For A Priority For Untagged Packets - Dell S6100 Configuration Manual

In ingress, the buffers are accounted at per PG basis and would indicate the number of the packets that has ingress this port PG but still
queued up in egress pipeline. However, there is no direct mapping between the PG and Queue.
Packet is assigned an internal priority on the ingress pipeline based on the queue to which it is destined. This Internal-priority to Queue
mapping has been modified and enhanced as follows for the device:
Table 19. Priority to Queue Mapping
0
Dot1p
Priority
1
Queue
Default dot1p to queue configuration is as follows:

Configuration Example for DSCP and PFC Priorities

Consider a scenario in which the following DSCP and PFC priorities are necessary:
DSCP 0 – 5, 10 - 15
Expected PFC 1
Priority
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.
Dell(conf)#do show qos dot1p-queue-mapping
Dot1p Priority : 0
Queue : 1
3 Dot1p->Queue Mapping Configuration is retained at the default value.
4 Interface Configurations on server connected ports.
a Enable DCB globally.
Dell(conf)#dcb enable
b Apply PFC Priority configuration. Configure priorities on which PFC is enabled.

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

Generation of PFC for a Priority for Untagged Packets

In order to generate PFC for a particular priority for untagged packets, and configuring PFC for that priority, you should find the queue
number associated with priority from TABLE 1 and Associate a DCB map to forward the matched DSCP packet to that queue. PFC frames
gets generated with PFC priority associated with the queue when the queue gets congested.
262 Data Center Bridging (DCB)
1 2
0 2
20 – 25, 30 – 35
2
1 2 3 4 5 6
0 2 3 4 5 6
3 4
3 4
7
7
5 6
5 6
7
7