Users Guide

Figure 29. Enhanced Transmission Selection
The following table lists the trac groupings ETS uses to select multiprotocol trac for transmission.
Table 13. ETS Trac Groupings
Trac Groupings Description
Group ID A 4-bit identier assigned to each priority group. The range is from
0 to 7 congurable; 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:
• 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 conguration 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 conguration on a peer link.
• Conguration 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 specic TLVs in LLDP data units. The following LLDP TLVs are supported for DCB parameter
exchange:
PFC parameters
PFC Conguration TLV and Application Priority Conguration TLV.
ETS parameters ETS Conguration TLV and ETS Recommendation TLV.
Data Center Bridging (DCB) 233