Users Guide
CONFIGURATION mode
Dell(conf)# interface fo 1/4 
INTERFACE mode
Dell(conf-if-fo-1/4)# ip address 90.1.1.1/16 
2  Congure a Layer 2 QoS policy with Layer 2 (Dot1p or source MAC-based) match criteria.
CONFIGURATION mode
Dell(conf)# policy-map-input l2p layer2 
3  Apply the Layer 2 policy on a Layer 3 interface.
INTERFACE mode
Dell(conf-if-fo-1/4)# service-policy input l2p layer2
Managing Hardware Buer Statistics
The memory management unit (MMU) is 12.2 MB in size. It contains approximately 60,000 cells, each of which is 208 bytes in size. MMU 
also has another portion of 3 MB allocated to it. The entire MMU space is shared across a maximum of 104 logical ports to support the 
egress admission-control functionality to implement scheduling and shaping on per-port and per-queue levels. Also, the MMU buer cells 
can be used by each port or queue either as a static partition or as a dynamic partition. With dynamic mode, you can specify the 
percentage of available buer that is utilized by a queue. This dynamic partition or block is set to be two-thirds of the available buers for 
all unicast queues and one-fth of the available buers for all multicast queues on these platforms.
The maximum number of ports, including fan-out, supported is 104 and the maximum number of queues supported is 21. Analyzing and 
evaluating buer statistics enables monitoring of resources and tuning of allocation of buers. Max Use count mode provides the maximum 
values of counters accumulated over a period of time. Current Use count mode enables you to obtain a snapshot of the counters, at a 
particular time, using a triggering utility. The trigger can either be software-based or based on a predetermined threshold event. Software-
based triggers are supported, which are the values derived from the show command output in the Max Use count mode. In Dell 
Networking OS Release 9.3(0.0), only the Max Use count mode of operation is supported for the computation of maximum counter values.
Depending on the buer space statistical values that you can obtain, you can modify the settings for buer area to achieve enhanced 
reliability and eciency in the handling of packets. This evaluation and administration of buer statistics is useful and important in 
deployments that experience congestion frequently. The receive buer must be large enough to save all data that is received when the 
system processes a PFC PAUSE frame.
You can use the service-class buffer shared-threshold-weight queue0 ... queue7 number command in Interface 
Conguration mode to specify the threshold weight for the shared buer for each of the queues per port.
1 Create a 10-Gigabit Ethernet interface. 
Dell(conf)#interface TenGigabitEthernet 1/1/1/1
2 Congure the threshold weight of the shared buer for the queues you want. In this example, this setting is congured for queues 5 
and 7. 
Dell(conf-if-te-1/1/1/1)#Service-class buffer shared-threshold-weight queue5 4 queue7 6 
Enabling Buer Statistics Tracking 
You can enable the tracking of statistical values of buer spaces at a global level. The buer statistics tracking utility operates in the max 
use count mode that enables the collection of maximum values of counters.
To congure the buer statistics tracking utility, perform the following step:
1  Enable the buer statistics tracking utility and enter the Buer Statistics Snapshot conguration mode.
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Quality of Service (QoS)










