Dell PowerEdge XL 5133-4 MXL 10/40GbE Switch IO Module FTOS Command Reference - Page 68
ETS uses the DCB MIB IEEE802.1azd2.5., Enhanced Transmission Selection
View all Dell PowerEdge XL 5133-4 manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 68 highlights
www.dell.com | support.dell.com Although you can configure strict-priority queue scheduling for a priority group, ETS introduces flexibility that allows the bandwidth allocated to each priority group to be dynamically managed according to the amount of LAN, storage, and server traffic in a flow. Unused bandwidth in a priority-group is dynamically allocated to other priority groups for which traffic is available to be scheduled. Traffic is queued according to its 802.1p priority assignment, while flexible bandwidth allocation and the configured queue-scheduling for a priority group is supported. Figure 6-2 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 6-2. Enhanced Transmission Selection ETS uses the following traffic groupings to select multiprotocol traffic for transmission: • Priority group: A group of 802.1p priorities used for bandwidth allocation and queue scheduling. All 802.1p priority traffic in a group should have the same traffic handling requirements for latency and frame loss. • Group ID: A 4-bit identifier assigned to each priority group. Valid values are from 0 to 7. • Group bandwidth: Percentage of available bandwidth allocated to a priority group. • Group transmission selection algorithm (TSA): Type of queue scheduling used by a priority group. ETS is implemented as follows in FTOS: • 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 Credit-based shaping is not supported. • ETS uses the DCB MIB IEEE802.1azd2.5. 54 | Data Center Bridging (DCB)