Dell S4048-ON, Configuration Manual

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QoS dot1p Traffic Classification and Queue Assignment
The following section describes QoS dot1P traffic classification and assignments.
DCB supports PFC, ETS, and DCBx to handle converged Ethernet traffic that is assigned to an egress queue according to the
following QoS methods:
Honor dot1p You can honor dot1p priorities in ingress traffic at the port or global switch level (refer to Default dot1p to
Queue Mapping) using the
service-class dynamic dot1p
command in INTERFACE configuration
mode.
Layer 2 class maps You can use dot1p priorities to classify traffic in a class map and apply a service policy to an ingress port to
map traffic to egress queues.
NOTE: Dell Networking does not recommend mapping all ingress traffic to a single queue when using PFC and ETS.
However, Dell Networking does recommend using Ingress traffic classification using the
service-class dynamic
dot1p
command (honor dot1p) on all DCB-enabled interfaces. If you use L2 class maps to map dot1p priority traffic to
egress queues, take into account the default dot1p-queue assignments in the following table and the maximum number of
two lossless queues supported on a port (refer to
Configuring Lossless Queues ).
Although Dell Networking OS allows you to change the default dot1p priority-queue assignments (refer to Setting dot1p
Priorities for Incoming Traffic ), DCB policies applied to an interface may become invalid if you reconfigure dot1p-queue
mapping. If the configured DCB policy remains valid, the change in the dot1p-queue assignment is allowed.
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.
dot1p Value in
the Incoming
Frame
Egress Queue Assignment
0 0
1 0
2 0
3 1
4 2
5 3
6 3
7 3
dot1p Value in
the Incoming
Frame
Egress Queue Assignment
0 2
1 0
2 1
3 3
4 4
5 5
6 6
Data Center Bridging (DCB)
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