Quality of Service Guide Service Egress and Ingress QoS Policies
Edition: 01 3HE 11014 AAAC TQZZA 311
priority — the priority keyword is used to override the default enqueuing priority for all
packets received on an ingress SAP using this policy that match this rule. Specifying
the priority is optional. When a packet matches the rule, the enqueuing priority is only
overridden when the priority parameter is defined on the rule. If the packet matches
and the priority is not explicitly defined in the rule, the enqueuing priority is inherited
based on previous rule matches.
high — the high keyword is used in conjunction with the priority keyword. Setting the
enqueuing parameter to high for a packet increases the likelihood of enqueuing the
packet when the ingress queue is congested. Ingress enqueuing priority only affects
ingress SAP queuing; once the packet is placed in a buffer on the ingress queue, the
significance of the enqueuing priority is lost.
low — the low keyword is used in conjunction with the priority keyword. Setting the
enqueuing parameter to low for a packet decreases the likelihood of enqueuing the
packet when the ingress queue is congested. Ingress enqueuing priority only affects
ingress SAP queuing; once the packet is placed in a buffer on the ingress queue, the
significance of the enqueuing priority is lost.
dscp
Syntax dscp dscp-name [dscp-name...(up to 8 max)] [fc fc-name] [priority {high | low}]
no dscp dscp-name [dscp-name...(up to 8 max)]
Context config>qos>sap-ingress
Description This command explicitly sets the forwarding class and/or enqueuing priority when a packet is
marked with the DiffServ Code Point (DSCP) value contained in dscp-name. Adding a DSCP
rule on the policy forces packets that match the specified DSCP value to override the
forwarding class and enqueuing priority based on the parameters included in the DSCP rule.
When the forwarding class is not specified in the rule, a matching packet preserves (or
inherits) the existing forwarding class derived from earlier matches in the classification
hierarchy. When the enqueuing priority is not specified in the rule, a matching packet
preserves (or inherits) the existing enqueuing priority derived from earlier matches in the
classification hierarchy.
The DSCP value (referred to by dscp-name) is derived from the most significant six bits in the
IP header ToS byte field (DSCP bits). The six DSCP bits define 64 DSCP values used to map
packets to per-hop QoS behavior.
A list of up to 8 DSCP names can be specified to assign DSCP values to an FC mapping for
DSCP classification.
The no form of this command removes the DiffServ code point to forwarding class
association. The default-action then applies to that code point value.
Parameters dscp-name — the dscp-name is a required parameter that specifies the unique IP header
ToS byte DSCP bits value that will match the DSCP rule.
To Next Page
Loading...
