Users Guide

PP (KB) (KB) (KB)
(KB) (KB)
-----------------------------------------------------------------------------------------
------------
1 0.0 3399 2656 1040 1040 576
1 0.1 3399 2656 1040 1040 576
1 0.2 3399 2656 1040 1040 576
1 0.3 3399 2656 1040 1040 576
DellEMC#
The default DCB buffer configuration supports 64 PFC lossless queues of 10G interface speed on each of the XPEs. The
following table shows the PFC buffer required for one loss less queue on various supported interface speeds:
Table 17. PFC Buffer required on one Loss Less Queue
Interface Speed PFC Buffer required for 1 lossless queue
10G 54KB
25G 94KB
40G 94KB
50G 161KB
100G 161KB
DCB Buffer value after PFC configuration:
When PFC is configured on a particular port, two XPEs corresponding to the ingress pipe to which the port belongs is updated
with the buffer values. If the port is on the ingress pipe 0 or 3, both the XPE A are updated. Where as, if the port is on ingress
pipe 1 or 2, then both the XPE B are updated.
The following example shows DCB buffer values after one PFC lossless queue configured on a port that belongs to ingress pipe
0 [10G speed]:
DellEMC#
DellEMC#show dcb
DCB Status: Enabled, PFC Queue Count: 2
Total Buffer: Total available buffer excluding the buffer pre-allocated
for guaranteed services like global headroom, queue's min
guaranteed buffer and CPU queues.
PFC Total Buffer: Maximum buffer available for lossless queues.
PFC Shared Buffer: Buffer used by ingress priority groups for shared usage.
PFC Headroom Buffer: Buffer used by ingress priority group for shared headroom usage.
PFC Available Buffer: Current buffer available for new lossless queues to be
Provisioned.
stack-unit Total Buffer PFC Total Buffer PFC Shared Buffer PFC Headroom Buffer PFC
Available Buffer
PP (KB) (KB) (KB)
(KB) (KB)
-----------------------------------------------------------------------------------------
------------
1 0.0 3399 2656 1040 1040 567
1 0.1 3399 2656 1040 1040 576
1 0.2 3399 2656 1040 1040 567
1 0.3 3399 2656 1040 1040 576
DellEMC#
Following table shows the XPE numbering scheme in Dell EMC Networking OS:
Data Center Bridging (DCB)
253