Quality of Service
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OmniAccess 5740 Unified Services Gateway CLI Configuration Guide
Alcatel-Lucent
ALCATEL-LUCENT SPECIFIC OVERVIEW ON QOS
QoS functionality and features supported are implemented at two stages - ingress
QoS processing and egress QoS processing. Ingress QoS processing deals with
features that are applicable while the packet gets into the OmniAccess 5740 USG.
For e.g., policing is a feature that admits packets into the system only if they arrive
at a committed rate. Policing functionality is normally applied at the ingress QoS
processing stage. Egress QoS processing deals with features that are applicable
to packets that leaves the OmniAccess 5740 USG. For e.g., shaping that fits the
outgoing traffic in to a committed rate envelope, is implemented at the egress
QoS processing stage.
Packets at the ingress are classified using common classifier, and exploits the
one-pass classification feature on the OmniAccess 5740 USG. These packets,
based on classification are grouped into a class. QoS is applied on each flow.
F
EATURES SUPPORTED BY OMNIACCESS 5740 USG
1. Traffic policy definition and policy management
2. Packet Classification
• Multi-field packet classification
• Behavior Aggregate (BA) classification
• TOS/Precedence based classification
3. Packet Queuing
• Per interface queuing
• Weighted Fair Queuing
• CBQ (Class Based Queuing)
• Strict priority scheduling
• DSCP to queue mapping, user configurable
• A policy map can have a maximum of 16 classes
including the default traffic
class -‘class-default’.
• One can be a default class ‘class-default’ and another one can be a
network-control class.
• 14 classes are used for shaping.
• The class-default traffic class is a non-priority class.
• There will be an L2 network control class on the egress side, which
schedules control packets and is of the highest priority.
• Priority and network-control commands are not applicable for class-default
traffic class.
4. Congestion Management
• Tail Drop
• Active queuing using WRED
• Ingress traffic conditioning
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