Reference Guide

Lossless traffic egresses out the no-drop queues. Ingress dot1p traffic from PFC-enabled interfaces is automatically mapped to
the no-drop egress queues.
1. Enter INTERFACE Configuration mode.
CONFIGURATION mode
interface type slot/port
2. Configure the port queues that will still function as no-drop queues for lossless traffic.
INTERFACE mode
pfc no-drop queues queue-range
For the dot1p-queue assignments, refer to the dot1p Priority-Queue Assignment table.
The maximum number of lossless queues globally supported on the switch is two.
The range is from 0 to 3. Separate the queue values with a comma; specify a priority range with a dash; for example, pfc
no-drop queues 1,3 or pfc no-drop queues 2-3.
The default: No lossless queues are configured.
NOTE: Dell Networking OS Behavior: By default, no lossless queues are configured on a port.
A limit of two lossless queues is supported on a port. If the amount of priority traffic that you configure to be paused exceeds
the two lossless queues, an error message displays.
In Z9500, any pfc-dot1p priorities configured on a given interface need not be the same across the system. In other words,
lossless queue limit is applicable on a per-port level and not on the global-config context. For example, one of the Te/Fo
interfaces can have pfc-dot1p priorities as 2 and 3. Whereas, the other Te/Fo interface(s) can have its pfc-dot1p priorities as 4
and 5.
It is the user responsibility to have symmetric PFC configurations on the interfaces involved in a particular PFC-enabled traffic-
flow to obtain lossless behavior.
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.
For example, storage traffic is sensitive to frame loss; interprocess communication (IPC) traffic is latency-sensitive. ETS allows
different traffic types to coexist without interruption in the same converged link by:
● Allocating a guaranteed share of bandwidth to each priority group.
● Allowing each group to exceed its minimum guaranteed bandwidth if another group is not fully using its allotted bandwidth.
ETS Prerequisites and Restrictions
The following prerequisites and restrictions apply when you configure ETS bandwidth allocation or queue scheduling.
● Configuring ETS bandwidth allocation or a queue scheduler for dot1p priorities in a priority group is applicable if the DCBx
version used on a port is CIN (refer to Configuring DCBx).
● When allocating bandwidth or configuring a queue scheduler for dot1p priorities in a priority group on a DCBx CIN interface,
take into account the CIN bandwidth allocation (refer to Configuring Bandwidth Allocation for DCBx CIN) and dot1p-queue
mapping.
NOTE: The IEEE 802.1Qaz, CEE, and CIN versions of ETS are supported.
Creating an ETS Priority Group
An ETS priority group specifies the range of 802.1p priority traffic to which a QoS output policy with ETS settings is applied on
an egress interface.
1. Configure a DCB Map.
CONFIGURATION mode
Data Center Bridging (DCB)
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