Qos Overview - Alcatel-Lucent 7950 Quality Of Service Manual

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QoS Overview

Routers are designed with Quality of Service (QoS) mechanisms on both ingress and egress to
support multiple customers and multiple services per physical interface. The router has an
extensive and flexible capabilities to classify, police, shape and mark traffic.
In the Alcatel-Lucent service router's service model, a service is provisioned on the provider-edge
(PE) equipment. Service data is encapsulated and then sent in a service tunnel to the far-end
Alcatel-Lucent service router where the service data is delivered.
The operational theory of a service tunnel is that the encapsulation of the data between the two
Alcatel Lucent service routers (such as the 7950 XRS, 7750 SR, 7710 SR, 7750 SR MG and 7450
ESS) appear like a Layer 2 path to the service data although it is really traversing an IP or IP/
MPLS core. The tunnel from one edge device to the other edge device is provisioned with an
encapsulation and the services are mapped to the tunnel that most appropriately supports the
service needs.
The router supports eight forwarding classes internally named: Network-Control, High-1,
Expedited, High-2, Low-1, Assured, Low-2 and Best-Effort. The forwarding classes are discussed
in more detail in
Router use QoS policies to control how QoS is handled at distinct points in the service delivery
model within the device. There are different types of QoS policies that cater to the different QoS
needs at each point in the service delivery model. QoS policies are defined in a global context in
the router and only take effect when the policy is applied to a relevant entity.
QoS policies are uniquely identified with a policy ID number or name. Policy ID 1 or Policy ID
"default" is reserved for the default policy which is used if no policy is explicitly applied.
The QoS policies within the router can be divided into three main types:
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Forwarding Classes on page
QoS policies are used for classification, defining and queuing attributes and marking.
Scheduler policies determine how queues are scheduled.
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7950 XRS Quality of Service Guide