Quality of Service
ExtremeWare XOS 11.3 Concepts Guide
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802.1p information on the BlackDiamond 10K only. If a port is in more than one virtual router, you cannot
use the QoS 802.1p features. The default VLAN DiffServ examination mappings apply on ports in more
than one VR. If you attempt to configure examining or replacing 802.1p information on a port that is in
more than one virtual router, the system returns the following message:
Warning: Port belongs to more than one VR. Port properties related to diff serv and
code replacement will not take effect.
Observing 802.1p information. When ingress traffic that contains 802.1p prioritization information is
detected by the switch, that traffic is mapped to various queues on the egress port of the switch. The
BlackDiamond 10K switch supports 8 hardware queues by default; you can modify the characteristics of
each queue. By default, the BlackDiamond 8800 family of switches and the Summit X450 switch support
2 queues based on flows; you can define up to 6 additional queues. The transmitting queue determines
the characteristics used when transmitting packets.
NOTE
See for Chapter 9 information regarding VMANs using 802.1p information to direct packets to appropriate egress
QoS queues.
To control the mapping of 802.1p prioritization values to queues, 802.1p prioritization values can be
mapped to a QoS profile. The default mapping of each 802.1p priority value to QoS profile is shown in
Table 43.
Changing the default 802.1p mapping. By default, a QoS profile is mapped to a queue, and each QoS
profile has configurable parameters. In this way, an 802.1p priority value seen on ingress can be
mapped to a particular QoS profile.
To change the mapping of 802.1p priority value to QoS profile, use the following command:
configure dot1p type <dot1p_priority> {qosprofile} <qosprofile>
Table 43: Default 802.1p priority value-to-QoS profile mapping
Priority value
BlackDiamond 10K switch
default QoS profile
BlackDiamond 8800 family of switches and Summit
X450 switch default QoS profile
0 QP1 QP1
1 QP2 QP1
2 QP3 QP1
3 QP41 QP1
4 QP5 QP1
5 QP6 QP1
6 QP7 QP1
7 QP8 QP8