Lenovo ThinkSystem NE2552E, Application Manual

Page: 247 / 574

© Copyright Lenovo 2018 Chapter 15: Fibre Channel over Ethernet
247
Effects on 802.1p Quality of Service
While CEE is off (the default), the NE2552E allows 802.1p priority values to be used
for Quality of Service (QoS) configuration (see the Application Guide ). 802.1p QoS
default settings are shown in Table 22 on page 247 , but can be changed by the
administrator.
When CEE is turned on, 802.1p QoS is replaced by ETS (see “Enhanced
Transmission Selection” on page 260 ). As a result, while CEE is turned on, using
802.1p QoS configuration commands causes an error message to appear stating
that the CEE global ETS command must be used to configure 802.1p ‐ based QoS.
In addition, when CEE is turned on, prior 802.1p QoS settings are replaced with
new defaults designed for use with ETS priority groups (PGIDs) as shown in
Table 22 :
When CEE is on, the default ETS configuration also allocates a portion of link
bandwidth to each PGID as shown in Table 23 :
If the prior, non ‐ CEE configuration used 802.1p priority values for different
purposes, or does not expect bandwidth allocation as shown in Table 23 on
page 247 , when CEE is turned on, the administrator should reconfigure ETS
settings as appropriate.
Table 22.
CEE Effects on 802.1p Defaults
802.1p QoS Configuration
With CEE Off (default)
ETS Configuration
With CEE On
Priority COSq Weight Priority COSq PGID
0 0 1 0 0 0
1 1 2 1 0 0
2 2 3 2 0 0
3 3 4 3 1 1
4 4 5 4 2 2
5 5 7 5 2 2
6 6 15 6 2 2
7 7 0 7 2 2
Table 23.
Default ETS Bandwidth Allocation
PGID Typical Use Bandwidth
0 LAN 10%
1 SAN 50%
2 Latency ‐ sensitive LAN 40%