Addendum
dot1p Value in the
Incoming Frame
Egress Queue Assignment
1 0
2 0
3 1
4 2
5 3
6 3
7 3
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.
3. Configure 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 configuration is handled as follows:
• ETS TLVs are supported in DCBx versions CIN, CEE, and IEEE2.5.
• The DCBx port-role configurations determine the ETS operational parameters (refer to Configure a
DCBx Operation).
• ETS configurations 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 configurations are ignored and existing ETS configurations are reset to the previously
configured ETS output policy on the port or to the default ETS settings if no ETS output policy was
previously applied.
542
Data Center Bridging (DCB)