Effects On 802.1P Quality Of Service - Lenovo Flex System Fabric CN4093 Application Manual

Effects on 802.1p Quality of Service

266
CN4093 Application Guide for N/OS 8.2
While CEE is off (the default), the CN4093 allows 802.1p priority values to be used
for Quality of Service (QoS) configuration (see "Quality of Service" on page
802.1p QoS default settings are shown in Table 28 on page
by the administrator.
When CEE is turned on, 802.1p QoS is replaced by ETS (see "Enhanced
Transmission Selection" on page
802.1p QoS configuration commands are no longer available on the switch (the
menu is restored when CEE is turned off).
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 28:
Table 28.
CEE Effects on 802.1p Defaults
802.1p QoS Configuration
With CEE Off (default)
Priority COSq
0 0
1 1
2 2
3 3
4 4
5 5
6 6
7 7
When CEE is on, the default ETS configuration also allocates a portion of link
bandwidth to each PGID as shown in Table
Table 29.
Default ETS Bandwidth Allocation
PGID Typical Use
0 LAN
1 SAN
2 Latency‐sensitive LAN
If the prior, non‐CEE configuration used 802.1p priority values for different
purposes, or does not expect bandwidth allocation as shown in Table 29 on
page 266, when CEE is turned on, the administrator should reconfigure ETS
settings as appropriate.
Each time CEE is turned on or off, the appropriate ETS or 802.1p QoS default
settings shown in Table 28 on page
to prior ETS or 802.1p QoS configurations are cleared.
278). As a result, while CEE is turned on, the
Weight Priority
1
2
3
4
5
7
15
0
29:
Bandwidth
10%
50%
40%
266 are restored, and any manual settings made
266, but can be changed
ETS Configuration
With CEE On
COSq PGID
0 0
1 0
2 0
3 1
4 2
5 2
6 2
7 2
185).
0
0
0
1
2
2
2
2