Users Guide

Honor DSCP priority on ingress trac
OS10(config)# policy-map policy-trust
OS10(conf-pmap-qos)# class class-trust
OS10(conf-pmap-c-qos)# trust diffserv
View policy-map
OS10(conf-pmap-c-qos)# do show policy-map
Service-policy (qos) input: policy-trust
Class-map (qos): class-trust
trust diffserv
Strict priority queuing
OS10 uses queues for egress QoS policy-types. You can enable priorities to dequeue all packets from the assigned queue before servicing
any other queues. When more than one queue is assigned strict priority, the highest number queue receives the highest priority. You can
congure strict priority to any number of queues. By default, all queues schedule trac per WDRR.
You can use the priority command to assign the priority to a single unicast queue—this conguration supersedes the bandwidth
percent
conguration. A queue with priority enabled can starve other queues for the same egress interface.
Consider the following when enabling priority queueing in S5148F-ON:
• In a port, one H2 node and three H1 nodes are supported. The H1 node holds 8 unicast queues for data trac, 8 unicast queues for
control trac, and 8 multicast queues for data trac.
• The H1 nodes mapped to data trac are scheduled with DWRR and weight of 50 each. The H1 node mapped to control trac is
scheduled with strict priority.
• The weights corresponding to each trac class are applied at queue levels for both unicast and multicast queues.
• The bandwidth distribution might go to a minimum of 50, based on the trac ow in a port. This is determined by the weight of a
particular trac class and trac type.
• The bandwidth sharing based on ETS happens only between same type of queues.
• You can enable strict priority queuing only for the same type of trac.
Create class-map
1 Create a class-map, and congure a name for the class-map in CONFIGURATION mode.
class-map type queuing class-map-name
2 Congure a match criteria in CLASS-MAP mode.
match queue queue-id
Dene a policy-map
1 Dene a policy-map, and create a policy-map name CONFIGURATION mode.
policy-map type queuing policy-map-name
2 Create a QoS class and congure a name for the policy-map in POLICY-MAP mode.
class class-map-name
3 Set the scheduler as the strict priority in POLICY-MAP-CLASS-MAP mode.
priority
Apply policy-map
1 You can now apply the policy-map to the interface (INTERFACE mode) or all interfaces—SYSTEM-QOS mode.
system qos
OR
interface ethernet node/slot/port[:subport]
2 Enter the output service-policy in SYSTEM-QOS mode or INTERFACE mode.
service-policy {output} type {queuing} policy-map-name
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Quality of service