Connectivity Guide

– Lossless pool (PFC)
• Egress buer pools:
– Lossy pool (default)
– Lossless pool (PFC)
– CPU pool (CPU control trac)
For example, when all ports are allocated as reserved buers from the lossy (default) pool, the remaining buers in the lossy pool are
shared across all ports, except the CPU port.
When you enable priority ow control (PFC) on the ports, all the PFC-enabled queues and priority-groups use the buers from the lossless
pool.
OS10 dedicates a separate buer pool for CPU trac. All default reserved buers for the CPU port queues are from the CPU pool. The
remaining buers are shared across all CPU queues. You can modify the buer settings of CPU queues.
You can congure the size of the CPU pool using the control-plane-buffer-size command.
OS10 allows conguration of buers per priority-group and queue for each port.
Buer-usage accounting happens for ingress packets on ingress pools and egress packets on egress pool. You can congure ingress-packet
buer accounting per priority-group and egress-packet buer accounting per queue level.
Congure ingress buer
In default ingress buers, all trac classes map to the default priority group. The buers are reserved per default priority group ID 7. All
buers are part of the default pool and all ports share buers from the default pool.
The reserved buer size is 9360 bytes for the speed of 10G, 25G, 40G, 50G, and 100G. The supported speed varies for dierent platforms.
Table 49. Maximum
buer size
Platforms Max buer size
S4000 12 MB
S6010–ON, S4048–ON 16 MB
S41xx 12 MB
Z9100–ON 16 MB
The following lists the link-level ow control (LLFC) buer settings for default priority group 7.
Table 50. Default setting for LLFC
Speed 10G 25G 40G 50G 100G
Default reserved buer 45KB 45KB 111KB 111KB 111KB
Default Xo threshold 36KB 36KB 75KB 75KB 75KB
Default Xon threshold 9KB 9KB 36KB 36KB 36KB
The following table lists the priority ow control (PFC) buer settings per PFC priority group.
Quality of service
791