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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 30. Enhanced Transmission Selection
The following table lists the traffic groupings ETS uses to select multiprotocol traffic for transmission.
Table 16. 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 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.
Data Center Bridging Exchange Protocol (DCBx)
DCBx allows a switch to automatically discover DCB-enabled peers and exchange configuration information. PFC and ETS use
DCBx to exchange and negotiate parameters with peer devices. DCBx capabilities include:
● Discovery of DCB capabilities on peer-device connections.
● Determination of possible mismatch in DCB configuration on a peer link.
● Configuration of a peer device over a DCB link.
DCBx requires the link layer discovery protocol (LLDP) to provide the path to exchange DCB parameters with peer devices.
Exchanged parameters are sent in organizationally specific TLVs in LLDP data units. The following LLDP TLVs are supported for
DCB parameter exchange:
PFC parameters
PFC Configuration TLV and Application Priority Configuration TLV.
ETS parameters ETS Configuration TLV and ETS Recommendation TLV.
Data Center Bridging (DCB) 247