You can configure class of service (CoS) for all subscribers that successfully establish connection to the broadband network. After you create the CoS profile, you can attach it to subscriber interfaces using a dynamic profile.
Configuring a CoS profile includes the following general steps:
In this configuration, we configure three forwarding classes, each with its own scheduler, and an IP precedence classifier for the traffic destined for the access network. Table 9 provides an overview of the queue configuration:
Table 9: Class of Service Queue Configuration
Forwarding classes identify output queues for packets. For a classifier to assign an output queue to each packet, it must associate the packet with one of the following forwarding classes:
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Note: The MX-series router enables you to configure up to eight forwarding class queues. |
To configure forwarding class queues:
- [edit]
- user@host#edit class-of-service forwarding-classes
queue 0
- [edit class-of-service forwarding-classes queue 0]
- user@host#set fc_be
- [edit]
- user@host#edit class-of-service forwarding-classes
queue 1
- [edit class-of-service forwarding-classes queue 1]
- user@host#set fc_ef
- [edit]
- user@host#edit class-of-service forwarding-classes
queue 2
- [edit class-of-service forwarding-classes queue 1]
- user@host#set fc_ef
CoS schedulers define the properties of output queues. These properties can include the amount of interface bandwidth assigned to the queue, the size of the memory buffer allocated for storing packets, the priority of the queue, and the random early detection (RED) drop profiles associated with the queue.
To configure CoS schedulers for the existing queues:
- [edit]
- user@host#edit class-of-service schedulers
sched_be
- [edit class-of-service schedulers sched_be]
- user@host#set buffer-size remainder
- [edit class-of-service schedulers sched_be]
- user@host#set prioritiy low
- [edit]
- user@host#edit class-of-service schedulers
sched_ef
- [edit class-of-service schedulers sched_ef]
- user@host#set transmit-rate 128k
- [edit class-of-service schedulers sched_ef]
- user@host#set buffer-size remainder
- [edit class-of-service schedulers sched_ef]
- user@host#set prioritiy strict-high
- [edit]
- user@host#edit class-of-service schedulers
sched_af
- [edit class-of-service schedulers sched_af]
- user@host#set transmit-rate 29400000
- [edit class-of-service schedulers sched_af]
- user@host#set buffer-size remainder
- [edit class-of-service schedulers sched_af]
- user@host#set prioritiy low
After configuring both CoS forwarding classes and schedulers, you must use scheduler maps to associate them.
To map CoS forwarding classes to schedulers:
- [edit]
- user@host#edit class-of-service scheduler-maps
SchedulerMap_Triple_Play_Basic
- [edit class-of-service scheduler-maps SchedulerMap_Triple_Play_Basic]
- user@host# edit forwarding-class fc_be
- [edit class-of-service scheduler-maps SchedulerMap_Triple_Play_Basic
forwarding-c lass fc_be]
- user@host#set scheduler sched_be
- [edit class-of-service scheduler-maps SchedulerMap_Triple_Play_Basic]
- user@host# edit forwarding-class fc_ef
- [edit class-of-service scheduler-maps SchedulerMap_Triple_Play_Basic
forwarding-c lass fc_ef]
- user@host#set scheduler sched_ef
- [edit class-of-service scheduler-maps SchedulerMap_Triple_Play_Basic]
- user@host# edit forwarding-class fc_af
- [edit class-of-service scheduler-maps SchedulerMap_Triple_Play_Basic
forwarding-c lass fc_af]
- user@host#set scheduler sched_af
You can override the default IP precedence classifier by defining a custom classifier. You can then apply the classifier to a logical interface.
To define a custom CoS classifier:
- [edit]
- user@host#edit class-of-service classifiers
dscp Class_DSCP
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Note: DSCP classifiers handle incoming IPv4 packets. |
- [edit class-of-service classifiers dscp Class_DSCP]
- user@host#edit forwarding-class fc_be
- [edit class-of-service classifiers dscp Class_DSCP forwarding-class
fc_be]
- user@host#edit loss-priority high
- [edit class-of-service classifiers dscp Class_DSCP forwarding-class
fc_be loss-p riority low]
- user@host#set code-points be
- [edit class-of-service classifiers dscp Class_DSCP]
- user@host#edit forwarding-class fc_ef
- [edit class-of-service classifiers dscp Class_DSCP forwarding-class
fc_ef]
- user@host#edit loss-priority low
- [edit class-of-service classifiers dscp Class_DSCP forwarding-class
fc_ef loss-p riority low]
- user@host#set code-points ef
- [edit class-of-service classifiers dscp Class_DSCP]
- user@host#edit forwarding-class fc_af
- [edit class-of-service classifiers dscp Class_DSCP forwarding-class
fc_af]
- user@host#edit loss-priority low
- [edit class-of-service classifiers dscp Class_DSCP forwarding-class
fc_af loss-p riority low]
- user@host#set code-points af41
Configuring CoS interface properties enables the router to throttle and classify the traffic from the Internet that is sent to subscriber local loops. Limiting the traffic to the access network ensures that the traffic sent to the subscriber local loops does not exceed the current data transmission rate of those lines. Limiting traffic also ensures that changes to subscriber local loop speeds do not cause bandwidth contention at the subscriber’s residential gateway. You apply the classifier to the core-facing interface to classify incoming traffic for the queues you are using in the access network.
To configure CoS interfaces:
- [edit]
- user@host#edit class-of-service interfaces
ge-1/3/0
- [edit class-of-service interfaces ge-1/3/0]
- user@host#edit class-of-service interfaces
ge-1/3/0 shaping-rate
- [edit class-of-service interfaces ge-1/3/0 shaping-rate]
- user@host#set 500m
- [edit]
- user@host#edit class-of-service interfaces
ge-1/3/1
- [edit class-of-service interfaces ge-1/3/1]
- user@host#edit unit 0
- [edit class-of-service interfaces ge-1/3/1 unit 0]
- user@host#edit classifiers
- [edit class-of-service interfaces ge-1/3/1 unit 0 classifiers]
- user@host#set dscp Class_DSCP