Shaping Input and Output Traffic on Ethernet IQ2 Interfaces

Gigabit Ethernet Intelligent Queuing 2 (IQ2) 4-port and 8-port Type 2 Physical Interface Cards (PICs) are oversubscribed, which means the amount of traffic coming to the PIC can be more than the maximum bandwidth from the PIC to the Flexible PIC Concentrator (FPC).

The 10-Gigabit Ethernet IQ2 PIC (xe-) is unlike other Gigabit Ethernet IQ2 PICs in that this PIC does not have oversubscription. The bandwidth from the PIC to the FPC is sufficient to transmit the full line rate. However, the 10-Gigabit Ethernet IQ2 PIC has the same hardware architecture as other Gigabit Ethernet IQ2 PICs and supports all the same class-of-service (CoS) features. For more information, see the PIC guide for your routing platform.

To handle oversubscribed traffic, you can configure input shaping and scheduling based on Layer 2, MPLS, and Layer 3 packet fields. Gigabit Ethernet IQ2 PICs also support simple filters, accounting, and policing. This chapter discusses input and output shaping and scheduling. For information about simple filters, see Example: Configuring a Simple Filter and the JUNOS Policy Framework Configuration Guide. For information about accounting and policing, see the JUNOS Network Interfaces Configuration Guide.

NOTE: The class-of-service (CoS) functionality supported on Gigabit Ethernet IQ2 PICs is not available across aggregated Ethernet links. However, if you configure a CoS scheduler map on the link bundle, the configuration is honored by the individual links within that bundle. Therefore, CoS on a per-link level behaves as configured, but CoS does not behave as configured across the aggregated links. For example, if you configure a shaping transmit rate of 100 megabits per second (Mbps) (by including the transmit-rate exact statement in a scheduler) on an aggregated Ethernet bundle with three ports, each port is provisioned with a 33.33 Mbps shaping transmit rate.

By default, transmission scheduling is not enabled on logical interfaces. Logical interfaces without shaping configured share a default scheduler. This scheduler has a committed information rate (CIR) that equals 0. (The CIR is the guaranteed rate.) The default scheduler has a peak information rate (PIR) that equals the physical interface shaping rate. The default operation can be changed by configuring the software.

To configure input and output shaping and scheduling, include the following statements at the [edit class-of-service] and [edit interfaces] hierarchy levels of the configuration:

[edit class-of-service]

traffic-control-profiles profile-name {

    delay-buffer-rate (percent percentage | rate);

    guaranteed-rate (percent percentage | rate);

    scheduler-map map-name;

    shaping-rate (percent percentage | rate);

}

interfaces interface-name {

    input-scheduler-map map-name;

    input-shaping-rate rate;

    scheduler-map map-name; # Output scheduler map

    shaping-rate rate; # Output shaping rate

    unit logical-unit-number {

        input-scheduler-map map-name;

        input-shaping-rate (percent percentage | rate);

        input-traffic-control-profile profile-name shared-instance instance-name;

        output-traffic-control-profile profile-name shared-instance instance-name;

    }

}

[edit interfaces interface-name]

per-unit-scheduler;

shared-scheduler;

This chapter discusses the following topics:

• Differences Between Gigabit Ethernet IQ and Gigabit Ethernet IQ2 PICs
• Configuring a Shared Scheduler and Shaper
• Differences Between Per-Unit Scheduling and Shared Scheduling
• Configuring Separate Input Schedulers
• Configuring Hierarchical Input Shapers
• Examples: Shaping Input and Output Traffic on Ethernet IQ2 Interfaces