Provides the physical 3RU compact chassis platform for Cisco ASR 9903 routing infrastructure. The chassis is intended for installations where the ASR 9903 architecture is required but rack space is constrained. Its compact enclosure format makes it distinct from larger chassis-based routing systems while retaining the role of a dedicated carrier-grade routing platform. SD-C4PK-A99RPFFC identifies the ASR 9903 compact chassis under Cisco Flexible Consumption. The designation matters when matching an installed platform, commercial configuration, and hardware requirement. This product is the chassis element of the system rather than a fixed-port switch, standalone appliance, cable, or add-in network adapter. Use this chassis where an ASR 9903 deployment calls for a 3RU physical platform. Plan the complete system configuration around the required routing components and site design, including the rack environment and platform-specific hardware selections. The compact 3RU format is the defining physical characteristic stated for this configuration, while the Flexible Consumption designation differentiates its ordering configuration within the ASR 9903 platform.