Static ATM Interfaces Within VC Subranges

You can configure a static ATM interface with an ATM PVC whose VPI and VCI addresses fall within an existing bulk-configured VC subrange. Conversely, you can also create a bulk-configured VC subrange that includes the VPI and VCI addresses belonging to an existing ATM PVC on a static ATM interface. Previously, configurations that caused VPI/VCI address conflicts between a static ATM interface and a bulk-configured VC subrange were prohibited on the router.

In certain ATM network configurations, you might need to transparently forward traffic from selected circuits with unrelated addresses to another location in the network. The ability to create a static ATM interface on a circuit within a bulk-configured VPI/VCI address range is particularly useful when you use ATM layer 2 services over MPLS with Martini encapsulation to forward the traffic from the selected circuits. You must create the interface stack for ATM layer 2 statically and define the configuration parameters individually on a per-interface basis.

The following rules apply when you configure either a static ATM interface within an existing bulk-configured VC subrange, or a subrange that includes an existing static ATM interface:

• All of the following ATM configurations are supported on the static ATM interface: ATM layer 2 services over MPLS including local cross-connects, point-to-point connections, and nonbroadcast multiaccess (NBMA) connections.
• Static ATM interfaces and circuits defined within a bulk-configured VC subrange are stored in NVS and preserved after a reboot.
• The base profile associated with the VC subrange does not apply to any statically defined ATM interfaces that fall within the subrange.
• If a VC subrange includes a statically defined ATM interface, overriding profile assignments configured for the same VPI/VCI address as a statically defined ATM interface become inactive until the static ATM 1483 subinterface is removed. The overriding profile becomes active again when you remove the static ATM 1483 subinterface. You can display the current operational status (active or inactive) of overriding profile assignments by using show atm bulk-config .
• Operations that add, remove, modify, merge, disable, or enable VC subranges within a bulk-configured VC range do not affect any static ATM interfaces defined within the VC subrange.
• You cannot create a static ATM circuit if the VPI/VCI address conflicts with an existing ATM 1483 dynamic subinterface column. Such a configuration would disrupt subscribers already connected to the router via the dynamic subinterface.
• You cannot create a static ATM interface with a VPI/VCI address that falls within a range of circuits reserved for use by the MPLS downstream-on-demand label distribution method.
• You cannot configure CAC on a static ATM interface within an existing bulk-configured VC subrange. Conversely, you cannot create a bulk-configured VC subrange that includes a static ATM interface on which CAC is configured. (For information about how to use the atm cac command to configure CAC, see Setting Optional Parameters in Configuring ATM .)

For configuration information and examples, see Configuring Static ATM Interfaces Within VC Subranges.

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