Concept Guide

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
NOTE: If you recongure the global dot1p-queue mapping, an automatic re-election of the DCBX conguration source port is
performed (refer to Conguration Source Election).
Congure Enhanced Transmission Selection
ETS provides a way to optimize bandwidth allocation to outbound 802.1p classes of converged Ethernet trac.
Dierent trac types have dierent service needs. Using ETS, you can create groups within an 802.1p priority class to congure dierent
treatment for trac with dierent bandwidth, latency, and best-eort needs.
For example, storage trac is sensitive to frame loss; interprocess communication (IPC) trac is latency-sensitive. ETS allows dierent
trac 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 congure 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 trac classes.
3 Congure a DCB output policy in which you associate a priority group with a QoS ETS output policy.
4 Apply the DCB output policy to an interface.
ETS Operation with DCBx
The following section describes DCBx negotiation with peer ETS devices.
In DCBx negotiation with peer ETS devices, ETS conguration is handled as follows:
• ETS TLVs are supported in DCBx versions CIN, CEE, and IEEE2.5.
• The DCBx port-role congurations determine the ETS operational parameters (refer to Congure a DCBx Operation).
• ETS congurations received from TLVs from a peer are validated.
• If there is a hardware limitation or TLV error:
– DCBx operation on an ETS port goes down.
– New ETS congurations are ignored and existing ETS congurations are reset to the previously congured ETS output policy on the
port or to the default ETS settings if no ETS output policy was previously applied.
• ETS operates with legacy DCBx versions as follows:
– In the CEE version, the priority group/trac class group (TCG) ID 15 represents a non-ETS priority group. Any priority group
congured with a scheduler type is treated as a strict-priority group and is given the priority-group (TCG) ID 15.
1016
FC Flex IO Modules