Reference Guide

The following table lists the maximum buffer size for different platforms.
Table 38. Maximum buffer size
Platforms Max buffer size
S4000 12 MB
S6010–ON, S4048–ON 16 MB
S41xx 12 MB
Z9100–ON 16 MB
Default settings for Link-level flow control (LLFC)
The following table lists the LLFC buffer settings for the default priority group 7.
Table 39. Default setting for LLFC
Speed 10G 25G 40G 50G 100G
Default reserved buffer 45KB 45KB 111KB 111KB 111KB
Default Xoff threshold 36KB 36KB 75KB 75KB 75KB
Default Xon threshold 9KB 9KB 36KB 36KB 36KB
Default settings for Priority flow control (PFC)
The following table lists the PFC buffer settings per PFC priority group.
Table 40. Default settings for PFC
Speed 10G 25G 40G 50G 100G
Default reserved buffer for S4000, S4048–ON, S6010–ON 9KB NA 9KB NA NA
Default reserved buffer for S41xx, Z9100–ON 9KB 9KB 18KB 18KB 36KB
Default Xoff threshold 36KB 45KB 75KB 91KB 142KB
Default Xon threshold 9KB 9KB 9KB 9KB 9KB
Default dynamic share buffer threshold(alpha value) 9KB 9KB 9KB 9KB 9KB
NOTE: The supported speed varies for different platforms. After the reserved buffers are utilized, each PFC starts
consuming shared buffers from the lossless pool with the threshold determined by the alpha value.
Configure priority group buffer settings
You can override the default priority group settings when LLFC or PFC is enabled.
1. Create network-qos type class-map to match the traffic classes. For LLFC match all the traffic classes(0-7) and for PFC,
match the required traffic class.
OS10(config)# class-map type network-qos tc
OS10 (config-cmap-nqos)# match qos-group 0-7
2. Create network-qos type policy-map to define the actions for traffic classes, like buffer configuration and thresholds.
OS10(config)# policy-map type network-qos buffer
OS10(config-pmap-network-qos)# class tc
OS10 (config-pmap-c-nqos)# pause buffer-size 300 pause-threshold 200 resume-threshold
100
OS10 (config-pmap-c-nqos)# queue-limit thresh-mode dynamic 5
Configure egress buffer
Default settings
642
Quality of service