C9404-FAN= Cisco Network Device Fan Tray

The Cisco ASR5K‑RCC‑K9 is a Redundancy Crossbar Card used in the Cisco ASR 5000 Series service‑provider routers to support the system’s high‑availability and resilient architecture. Rather than providing network interfaces to devices, this internal card forms part of the ASR 5000’s redundant midplane communication fabric, using multiple high‑speed serial links to interconnect rear‑mounted line cards and front‑loaded application/packet‑processing cards. By creating a shared crossbar network with up to 28 bidirectional links per RCC, it helps maintain data connectivity and session integrity even if one processing component fails, enabling traffic to be rerouted to redundant packet processors and minimizing service disruption in carrier‑grade deployments.