Dell Configuration Guide for the S4048–ON System 9.14.2.6

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Enhanced Transmission Selection

Enhanced transmission selection (ETS) supports optimized bandwidth allocation between traffic types in multiprotocol (Ethernet, FCoE, SCSI) links.

ETS allows you to divide traffic according to its 802.1p priority into different priority groups (traffic classes) and configure bandwidth allocation and queue scheduling for each group to ensure that each traffic type is correctly prioritized and receives its required bandwidth. For example, you can prioritize low-latency storage or server cluster traffic in a traffic class to receive more bandwidth and restrict best-effort LAN traffic assigned to a different traffic class.

NOTE Use the following command to enable etsacl: cam-acl l2acl 2 ipv4acl 2 ipv6acl 0 ipv4qos 0 l2qos 0 l2pt 0 ipmacacl 0 vman-qos 0 fcoeacl 2 etsacl 3. After executing this command, you must save the configuration and then reload the system.

The following figure shows how ETS allows you to allocate bandwidth when different traffic types are classed according to 802.1p priority and mapped to priority groups.

Illustration of enhanced transmission selection. — Figure 1. Enhanced Transmission Selection. Enhanced Transmission Selection

The following table lists the traffic groupings ETS uses to select multiprotocol traffic for transmission.

Table 1. ETS Traffic GroupingsETS Traffic Groupings
Traffic Groupings	Description

Group ID	A 4-bit identifier assigned to each priority group. The range is from 0 to 7 configurable; 8 - 14 reservation and 15.0 - 15.7 is strict priority group..
Group bandwidth	Percentage of available bandwidth allocated to a priority group.
Group transmission selection algorithm (TSA)	Type of queue scheduling a priority group uses.

In Dell EMC Networking OS, ETS is implemented as follows:

ETS supports groups of 802.1p priorities that have:
- PFC enabled or disabled
- No bandwidth limit or no ETS processing
ETS uses the DCB MIB IEEE 802.1azd2.5.