Congestion Management
Configuring QoS
page 25-12
OmniSwitch AOS Release 7 Network Configuration Guide
June 2013
•
The QSP assigned to the QSI for port 1/1 and port 2/1 is applied by the scheduler to all pVOQ flows
destined for port 1/1 or port 2/1.
•
There are four pre-defined QSPs supported. In this example, the default QSP 1 is associated with the
QSI for port 1/1. However, QSP 4 was assigned to the QSI for port 2/1.
•
QSP 1 and QSP 4 apply the default WRED profile 1 (WRP 1) to the QSI for port 1/1 and port 2/1.
(WRED is only supported on the OmniSwitch 6900).
•
The QSet framework shown in this example applies to unicast traffic. Selecting QSPs only applies to
unicast VOQ queue management.
Note that the VOQs that reside in the switch fabric, as represented by QSet instances, is just a state space
where configured and dynamic parameters for each VOQ is specified. There is no physical buffer memory
associated with these VOQs in the fabric. Packets are not buffered in fabric
Multicast Queues
Unicast and multicast traffic are both queued and funneled separately through the switch. The QSet frame-
work described in previous sections applies only to unicast traffic. Multicast traffic is queued based on the
destination multicast group ID for the packets. Pre-set queues and profiles associated with the MGID
handle the multicast traffic.
The multicast queue framework is not user-configurable, in that there are no user-configurable profiles.
However, the type of profile assigned to a port can determine the class of service for multicast traffic. For
more information, see
“Multicast and Unicast Traffic Distribution” on page 25-15
QSet Profiles
There are four pre-defined QSet profiles (QSP 1 - 4) supported. Each profile defines the following band-
width management attributes that are applied to traffic destined for the port or LAG QSet instance associ-
ated with the profile:
•
The percentage of bandwidth allocated for and shared by all of the QSet queues. This value is taken
from the port to which the QSet profile is applied (either port speed or the user-defined bandwidth for
the port is used).
•
The name and ID and administrative status of the WRED profile (WRP) that is applied to all of the
QSet queues. By default, WRP 1 is associated with each QSet profile.
•
The administrative status of statistics collection for the QSet queues.
•
The queue specific (QSpec) priority used for output scheduling on each of the eight QSet queues.
The following four pre-defined QSet profiles are supported:
To determine how flows are mapped to the egress queues based on ingress priority markings, see the
“QSet Profile Mapping (Unicast)” on page 25-13
. This section contains CoS priority mapping tables for
each QSet profile.
QSP
Default WRP
Bandwidth Queue Specific Priority
QSP 1
WRP 1
100%
8 SP
QSP 2
WRP 1
100%
1 EF, 7 SP
QSP 3
WRP 1
100%
1 EF, 7 WFQ
QSP 4
WRP 1
100%
1 EF, 2 SP, 4 AF, 1 BE