Configuration Notes: Pfc And Ets In A Dcb Map; Pfc Configuration Notes - Dell C9000 Series Networking Configuration Manual

Dell(conf)#
Dell(conf)#dcb enable pfc-queues ?
<1-4>
<1-4> Number of PFC lossless queues(default=2)
NOTE: In Egress queue assignment (8 queues).
PFC is not applied on specific dot1p priorities.
ETS: Equal bandwidth is assigned to each port queue and each dot1p priority in a priority group.
To configure PFC and ETS parameters on an interface, you must specify the PFC mode, the ETS bandwidth
allocation for a priority group, and the 802.1p priority-to-priority group mapping in a DCB map. No default
PFC and ETS settings are applied to Ethernet interfaces.
Configuration Notes: PFC and ETS in a
DCB Map
The switch supports the use of a DCB map in which you configure priority-based flow control (PFC) and
enhanced transmission selection (ETS) settings. To configure PFC and ETS parameters, you must apply a DCB
map on the interface.

PFC Configuration Notes

PFC provides flow control based on the 802.1p priorities in a converged Ethernet traffic that is received on an
interface and is enabled when you enable DCB. As an enhancement to the existing Ethernet pause
functionality, PFC stops traffic transmission for specified priorities (CoS values) without impacting other
priority classes. Different traffic types are assigned to different priority classes.
When traffic congestion occurs, PFC sends a pause frame to a peer device with the CoS priority values of the
traffic that needs to be stopped. DCBx provides the link-level exchange of PFC parameters between peer
devices. PFC allows network administrators to create zero-loss links for SAN traffic that requires no-drop
service, while at the same time retaining packet-drop congestion management for LAN traffic.
On the switch, PFC is enabled on Ethernet ports (pfc mode on command). You can configure PFC
parameters using a DCB map or the pfc priority command in Interface configuration mode. For more
information, see Configuring Priority-Based Flow
As soon as you apply a DCB map with PFC enabled on an interface, DCBx starts exchanging information with
a peer. The IEEE802.1Qbb, CEE and CIN versions of PFC TLV are supported. DCBx also validates PFC
configurations that are received in TLVs from peer devices. By applying a DCB map with PFC enabled, you
enable PFC operations on ingress port traffic. To achieve complete lossless handling of traffic, configure PFC
priorities on all DCB egress ports.
NOTE: DCB maps are supported only on physical Ethernet interfaces.
Number of PFC lossless queues(default=2)
Control.
Data Center Bridging (DCB) 303