Alcatel-Lucent 7450 Quality Of Service Manual page 277

low — This parameter is used in conjunction with the priority parameter. Setting the enqueuing
prec
Syntax prec ip-prec-value fc fc-name [hsmda-counter-override counter-id] [profile {in | out}]
no prec ip-prec-value
Context config>qos>sap-egress
Description This command defines a specific IP precedence value that must be matched to perform the associated
reclassification actions. If an egress packet on the SAP matches the specified IP precedence value, the
forwarding class, profile or HSMDA egress queue accounting behavior may be overridden. By default,
the forwarding class and profile of the packet is derived from ingress classification and profiling
functions. The default behavior for HSMDA queue accounting is to use the counters associated with
the queue to which the packet is mapped (applies to the 7450 ESS and 7750 SR).
The IP precedent bits used to match against prec reclassification rules come from the Type of Service
(ToS) field within the IPv4 header. If the packet does not have an IPv4 header, prec based matching is
not performed.
The reclassification actions from a prec reclassification rule may be overridden by a DHCP or IP flow
matching events.
The fc keyword is optional. When specified, the egress classification rule will overwrite the forwarding
class derived from ingress. The new forwarding class is used for egress remarking and queue mapping
decisions. If a dhcp or ip-criteria match occurs after the prec match, the new forwarding class may be
overridden by the higher priority match actions. If the higher priority match actions do not specify a
new fc, the fc from the prec match will be used.
The profile keyword is optional. When specified, the egress classification rule will overwrite the
profile of the packet derived from ingress. The new profile value is used for egress remarking and
queue congestion behavior. If a dhcp or ip-criteria match occurs after the prec match, the new profile
may be overridden by the higher priority match actions. If the higher priority match actions do not
specify a new profile, the profile from the prec match will be used.
Quality of Service Guide
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.
When the packet is placed in a buffer on the ingress queue, the significance of the enqueuing
priority is lost.
Default
Inherit (When priority is not defined, the rule preserves the
previous enqueuing priority of the packet.)
Values
high, low
Service Egress and Ingress QoS Policies
277