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Configuring Policing on an ATM IMA Pseudowire


On ACX Series routers, the ATM policer is attached to the ingress path of the ATM IMA interface, making it an input policer configured at the [edit firewall] hierarchy level. This input policer is then applied to an ATM IMA logical interface. The ATM IMA logical interface must have circuit cross-connect (CCC) family encapsulation configured for the configuration to work.

The following steps require you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode in the CLI User Guide.


Configuring policing on an ATM IMA pseudowire is not applicable on ACX5048 and ACX5096 routers.

This topic includes the following tasks:

Configuring an Input Policer

To configure policing on an ATM IMA pseudowire:

  1. Define the ATM IMA pseudowire. For information about defining the ATM IMA pseudowire, see Configuring Inverse Multiplexing for ATM (IMA) on ACX Series.
  2. In configuration mode, go to the [edit firewall] hierarchy level:
  3. Define the policer:

    The following steps describe the ATM policer options that you can configure. The options include: atm-service, cdvt, logical-interface-policer, max-burst-size, peak-rate, policing-action, and sustained-rate.

  4. Specify the ATM service category:

    Select one of the following service categories, depending on the policing needs of your network: constant bit rate (cbr), nonreal-time variable bit rate (nrtvbr), real-time variable bit rate (rtvbr), and unspecified bit rate ubr. All service categories must include the peak-rate and cdvt statements for the configuration to work. The peak-rate statement limits the maximum traffic allowed and the cdvt statement ensures that the configuration functions correctly.

  5. Apply limits to the traffic flow by configuring the cell delay variation tolerance (cdvt), from 1 microsecond through 1,800,000,000 microseconds:
  6. (Optional) Define the policer as a logical interface policer:

    The logical interface policer is associated with the interface on which the policer is applied. To configure the policer on multiple interfaces, you must apply this policer on each interface explicitly.

  7. (Optional) Define the maximum number of cells that a burst of traffic can contain, from 1 through 4000 cells:
  8. Apply limits to the traffic flow by specifying the largest number of cells per second that the policer processes before it drops packets, from 61 cells per second (cps) through 38,641 cps:

    The maximum peak rate value depends on the number of links in the IMA bundle—the more links, the higher the possible peak rate.

  9. Define the policing-action parameter to set a consequence for the packets that exceed the traffic limits:
  10. Define the normal traffic rate averaged over time, from 61 cps through 38,641 cps):

After you have configured policing, enter the commit command from configuration mode.

Configuring the ATM IMA Interface

To create the ATM IMA interface on which to apply the ATM policer:

  1. In configuration mode, go to the [edit interfaces] hierarchy level:
  2. Define the ATM interface:
  3. Specify the ATM interface unit:
  4. Apply the ATM policer:
  5. Specify the encapsulation family type:

After you have configured the ATM IMA interface, enter the commit command in configuration mode.