Users Guide

Enhanced Transmission Selection
Enhanced transmission selection (ETS) supports optimized bandwidth allocation between traffic types in
multiprotocol (Ethernet, FCoE, SCSI) links. By default, ETS is disabled.
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.
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.
Figure 29. Enhanced Transmission Selection
The following table lists the traffic groupings ETS uses to select multiprotocol traffic for transmission.
Table 14. ETS 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 Networking OS, ETS is implemented as follows:
• ETS supports groups of 802.1p priorities that have:
Data Center Bridging (DCB) 294