What Is the CP-7841-3PW-NA-K9=? Power, Compatibility, and Deployment Use Cases Analyzed

Product Overview

The ​​CP-7841-3PW-NA-K9=​​ is a ​​3-port 40 Gigabit Ethernet (40GE) Power over Ethernet (PoE+) module​​ for Cisco’s Catalyst 7800 Series switches. Designed for high-density enterprise and campus environments, it combines high-speed connectivity with ​​60W PoE++ per port​​, making it suitable for powering advanced endpoints like PTZ cameras, Wi-Fi 6E access points, and IoT gateways.

Core Technical Specifications

• ​​Port Configuration​​: 3 x 40GE QSFP28 ports with ​​IEEE 802.3bt (PoE++)​​
• ​​Total PoE Budget​​: ​​180W​​ (60W per port)
• ​​Forwarding Capability​​: ​​480 Gbps non-blocking throughput​​
• ​​Compatibility​​: Requires ​​Catalyst 7800 Series chassis​​ (C7800R Supervisor Engine or newer)
• ​​Power Efficiency​​: ​​SmartPower​​ allocates PoE dynamically based on device demands

Key Deployment Scenarios

​​1. High-Power IoT Deployments​​
Supports energy-intensive devices like ​​Cisco DNA Spaces sensors​​ and industrial automation equipment without external power sources.

​​2. Multi-Gig Campus Backbones​​
Enables ​​40GE uplinks​​ between access and core layers, critical for latency-sensitive applications like AR/VR collaboration tools.

​​3. Unified Access Solutions​​
Pairs with ​​Catalyst 9100AP Wi-Fi 6E access points​​ for converged wired/wireless management via Cisco DNA Center.

Addressing Critical User Concerns

​​Q: Can the CP-7841-3PW-NA-K9= operate in existing Catalyst 6800 chassis?​​
A: No—exclusive to ​​Catalyst 7800 Series switches​​ due to upgraded power architecture and airflow requirements.

​​Q: How does it handle mixed 10GE/40GE connectivity?​​
A: Uses ​​QSFP28-to-4xSFP28 breakout cables​​ for backward compatibility, converting one 40GE port into four 10GE links.

​​Q: What redundancy safeguards exist for PoE loads?​​
A: Features ​​per-port power policing​​ to prevent overloads and ​​N+1 power supply redundancy​​ when paired with dual 3kW AC/DC units.

Purchasing and Validation

For chassis compatibility checks and regional availability (NA-model specifics), refer to the Cisco Catalyst modules section at itmall.sale. Verify firmware requirements (​​IOS XE 17.9.1 or later​​) to enable PoE++ functionality.

Practical Evaluation

The ​​CP-7841-3PW-NA-K9=​​ fills a niche for enterprises needing to future-proof power and bandwidth in a single module. While its chassis exclusivity adds upfront costs, the elimination of external PoE injectors and simplified cable management offsets long-term operational expenses—provided teams can navigate its strict cooling requirements (5RU chassis minimum). For organizations scaling IoT or immersive tech, this module is a strategic investment; for smaller setups, standalone PoE switches may prove more cost-effective.