Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 279

fpStatsPerPgTable pfcPerPrioTable This table fetches the Allocated Min cells, Shared cells and Headroom cells per Priority Group, the mode in which the buffer cells are allocated - Static or Dynamic and the Used Min Cells, Shared cells and Headroom cells per Priority Group. The table fetches a value of 0 if the mode of allocation is Static and a value of 1 if the mode of allocation is Dynamic. This table is indexed by stack-unit number, port number and priority group number. This table fetches the number of PFC frames transmitted (PFC Requests) and the number of PFC frames received (PFC Indications) per priority on a per port basis. This table is indexed by the stack-unit index, port number and priority. DCB Maps and its Attributes This topic contains the following sections that describe how to configure a DCB map, apply the configured DCB map to a port, configure PFC without a DCB map, and configure lossless queues. DCB Map: Configuration Procedure A DCB map consists of PFC and ETS parameters. By default, PFC is not enabled on any 802.1p priority and ETS allocates equal bandwidth to each priority. To configure user-defined PFC and ETS settings, you must create a DCB map. The following is an overview of the steps involved in configuring DCB. 1. Enter global configuration mode to create a DCB map or edit PFC and ETS settings. 2. Configure the PFC setting (on or off) and the ETS bandwidth percentage allocated to traffic in each priority group, or whether the priority group traffic should be handled with strict priority scheduling. You can enable PFC on a maximum of 4 priority queues on an interface. Enabling PFC for dot1p priorities makes the corresponding port queue lossless. The sum of all allocated bandwidth percentages in all groups in the DCB map must be 100%. Strict-priority traffic is serviced first. Afterwards, you can configure either the peak rates or the committed rates. The bandwidth allocated to other priority groups is made available and allocated according to the specified percentages. If a priority group does not use its allocated bandwidth, the unused bandwidth is made available to other priority groups. 3. Repeat the above procedure to configure PFC and ETS traffic handling for each priority group 4. Specify the dot1p priority-to-priority group mapping for each priority. The priority group range is from 0 to 7. All priorities that map to the same queue must be in the same priority group. Leave a space between each priority group number. For example: priority-pgid 0 0 0 1 2 4 4 4 in which priority group 0 maps to dot1p priorities 0, 1, and 2; priority group 1 maps to dot1p priority 3; priority group 2 maps to dot1p priority 4; priority group 4 maps to dot1p priorities 5, 6, and 7. Important Points to Remember • If you remove a dot1p priority-to-priority group mapping from a DCB map (no priority pgid command), the PFC and ETS parameters revert to their default values on the interfaces on which the DCB map is applied. By default, PFC is not applied on specific 802.1p priorities; ETS assigns equal bandwidth to each 802.1p priority. As a result, PFC and lossless port queues are disabled on 802.1p priorities, and all priorities are mapped to the same priority queue and equally share the port bandwidth. • To change the ETS bandwidth allocation configured for a priority group in a DCB map, do not modify the existing DCB map configuration. Instead, first create a new DCB map with the desired PFC and Data Center Bridging (DCB) 279