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Configuring Shaping on 10-Gigabit Ethernet IQ2 PICs

The 10-Gigabit Ethernet IQ2 PIC (which has xe- interfaces) is unlike other Gigabit Ethernet IQ2 PICs in that it 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 Ethernet Interfaces User Guide for Routing Devices.

To handle oversubscribed traffic on 10-Gigabit Ethernet IQ2 PICs, 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 topic discusses input and output shaping and scheduling. For information about accounting and policing, see the Junos OS Network Interfaces Library for Routing Devices.

Note:

The 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 behaves as configured on a per-link level, but not across the aggregated links.

If you configure a shaping transmit rate of 100 Mbps on an aggregated Ethernet bundle with three ports (by applying a scheduler for which the configuration includes the transmit-rate statement with the exact option at the [edit class-of-service schedulers scheduler-name] hierarchy level), each port is provisioned with a 33.33 Mbps shaping transmit rate.

You can configure shaping for aggregated Ethernet interfaces that use interfaces originating from Gigabit Ethernet IQ2 PICs. However, you cannot enable shaping on aggregated Ethernet interfaces when the aggregate bundle combines ports from IQ and IQ2 PICs.

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 scheduling and shaping on 10-Gigabit Ethernet IQ2 PICs:


  1. Create the traffic-control profile, including the required scheduler map and shaping rate.

  2. Apply the traffic-control profile to logical interface for either input scheduling and shaping and/or output scheduling and shaping:

    To apply the traffic-control profile to a logical interface for input scheduling and shaping.

    To apply the traffic-control profile to a logical interface for output scheduling and shaping.

    To apply the traffic-control profile to a logical interface for both input and output scheduling and shaping.

  3. Enable per-unit scheduling (per-unit-scheduler statement) to enable the association of scheduler maps with logical interfaces.
Note:

The scheduler-map and shaping-rate statements can be specified at the [edit class-of-service interfaces interface-name unit logical-unit-number] hierarchy level. However, we do not recommend this configuration. Include the output-traffic-control-profile or input-traffic-control-profile statement instead.

Note:

For Gigabit Ethernet IQ2 interfaces, the logical interface egress statistics displayed in the show interfaces command output might not accurately reflect the traffic on the wire when output shaping is applied. Traffic management output shaping might drop packets after they are tallied by the Output bytes and Output packets logical interface counters. However, correct values display for both of these Transit statistics when per-unit scheduling is enabled for the Gigabit Ethernet IQ2 physical interface, or when a single logical interface is actively using a shared scheduler.

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