Figure 28. Enhanced Transmission Selection
The following table lists the traffic groupings ETS uses to select multiprotocol traffic for transmission.
Table 9. ETS Traffic Groupings
Traffic Groupings Description
Priority group A group of 802.1p priorities used for bandwidth
allocation and queue scheduling. All 802.1p priority
traffic in a group must have the same traffic
handling requirements for latency and frame loss.
Group ID A 4-bit identifier assigned to each priority group.
The range is from 0 to 7.
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 the Dell 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
• Bandwidth allocated by the ETS algorithm is made available after strict-priority groups are serviced. If
a priority group does not use its allocated bandwidth, the unused bandwidth is made available to
other priority groups.
• For ETS traffic selection, an algorithm is applied to priority groups using:
– Strict priority shaping
– ETS shaping
• ETS uses the DCB MIB IEEE 802.1azd2.5.
Data Center Bridging (DCB)
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