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 the system 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. For DCB ETS enabled interfaces, traffic destined
to queue that is not mapped to any dot1p priority are dropped.
dot1p Value in the
Incoming Frame
Egress Queue Assignment
00
10
20
31
42
53
63
73
NOTE: If you reconfigure the global dot1p-queue mapping, an automatic re-election of the DCBX
configuration source port is performed (refer to Configuration Source Election).
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.
To configure ETS and apply an ETS output policy to an interface, you must:
1. Create a Quality of Service (QoS) output policy with ETS scheduling and bandwidth allocation
settings.
2. Create a priority group of 802.1p traffic classes.
FC Flex IO Modules 1051