WS-C3850-24UW-S Cisco Catalyst 24 Ports Switch

Product Outline

The Cisco WS-C3850-24UW-S Catalyst 3850 Series Switch is a powerful enterprise-grade Ethernet switch designed to deliver high performance, scalability, and advanced network control. Built for modern business environments, this model supports reliable connectivity, efficient traffic handling, and simplified network management.

Manufacturer Information

Brand and Identity

• Manufacturer: Cisco Systems, Inc.
• Brand Name: Cisco
• Product Line: Catalyst
• Series: 3850
• Model Name: Catalyst 3850-24U Ethernet Switch
• Model Number: WS-C3850-24UW-S

Core Features and Capabilities

Network Ports and Connectivity

• Equipped with 24 high-speed Gigabit Ethernet ports
• Integrated uplink port for enhanced network expansion
• Stacking support for improved scalability and simplified management
• Non-modular design for stable and consistent performance

Port Specifications

Ethernet Interfaces

• 24 x 10/100/1000Base-T Gigabit Ethernet ports
• Supports twisted-pair cabling for flexible deployment

Performance and Network Technology

Advanced Switching Performance

• Gigabit Ethernet technology for fast data transmission
• Optimized for Layer 3 switching and routing capabilities
• Ensures low latency and high throughput for enterprise networks

Management and Control

Smart Network Administration

• Fully manageable switch for centralized network control
• Ideal for businesses requiring secure and efficient traffic management

Power Supply and Reliability

Power and Redundancy Options

• Powered by a reliable internal power supply
• Supports redundant power supply for maximum uptime

Physical Design

Form Factor and Mounting

• Compact 1U rack-compatible design
• Can be installed as rack-mountable or standalone

Dimensions

Size and Space Requirements

• Height: 1.8 inches
• Width: 17.7 inches
• Depth: 17.5 inches

Core Architecture: Cisco StackWise-480 and Unified Access

At the heart of the Catalyst 3850's innovation is its unique architecture, which fundamentally rethinks how wired and wireless networks are managed and operated.

The StackWise-480 Backplane Advantage

Unlike traditional standalone switches, the WS-C3850-24UW-S is built for stacking. The proprietary Cisco StackWise-480 technology allows up to nine individual switches to be logically combined into a single, unified switching entity. This creates a resilient, 480 Gbps stacking backplane for inter-switch communication. The benefits are transformative:

Single Management Point: An entire stack of switches is managed as one device, drastically simplifying configuration, troubleshooting, and software updates.
Enhanced Resiliency: The stack operates with a single control plane but distributed data planes. If the master switch fails, a subordinate switch automatically takes over with minimal disruption.
Scalable Performance: Bandwidth and port density scale linearly as you add units, providing a predictable growth path without complex uplink configurations.

Unified Access Data Plane (UADP) ASIC

Powered by Cisco's custom UADP application-specific integrated circuit (ASIC), this switch delivers feature parity and consistent policy enforcement for both wired and wireless clients. The UADP ASIC enables advanced features like Flexible NetFlow, detailed application visibility, and granular quality of service (QoS) at wire speed, ensuring that network policies are applied uniformly regardless of how a device connects.

Detailed Port Configuration and Power over Ethernet Capabilities

The "24UW" in WS-C3850-24UW-S precisely defines its physical interface offering, tailored for modern, device-rich environments.

Port Breakdown and Capabilities

The switch provides a versatile mix of Ethernet interfaces:

24 x RJ-45 Copper Ports: All 24 downlink ports are multi-gigabit capable, supporting 10/100/1000 Mbps and, critically, IEEE 802.3af (PoE) and 802.3at (PoE+). This allows for the simultaneous powering of a vast array of devices.
4 x SFP+ Uplink Ports: Dedicated 10 Gigabit Ethernet SFP+ uplink ports provide high-bandwidth aggregation to the network core or data center. These ports support a wide range of Cisco SFP+ modules for fiber or copper Twinax connectivity, enabling flexible deployment over short or long distances.

Understanding PoE+ Budget: The "UW" Specification

The UW-S designation indicates a Universal software image with a High Power PoE+ budget. This model typically provides up to 440 Watts of total PoE power. This substantial budget is essential for powering high-demand devices such as:

802.11ac Wave 2 and Wi-Fi 6/6E Cisco Access Points, which often require full PoE+.IP telephones and video phones with large displays.
Advanced IP security cameras with pan-tilt-zoom (PTZ), heaters, or infrared illuminators.
Point-of-sale (POS) systems, wireless controllers, and thin clients.
Building automation devices and sensors.

Intelligent power management features ensure priority is given to critical devices, and power can be dynamically reallocated as devices are added or removed.

Software and Intelligence: Cisco IOS XE Network Operating System

The Catalyst 3850 runs on Cisco IOS XE, a modern, Linux-based operating system that provides the robustness of traditional IOS with enhanced modularity, serviceability, and programmability.

Programmability and Automation

IOS XE opens the platform to modern network operations paradigms:

Model-Driven Programmability: Support for YANG data models and NETCONF/RESTCONF APIs allows for automated, zero-touch provisioning and configuration management using tools like Ansible, Puppet, or Python scripts.
Open API Ecosystem: Developers can create custom applications that interact directly with the switch to extract telemetry data or implement unique business logic.
On-Box Python Scripting: Python interpreters can run directly on the switch, enabling localized automation scripts for event-driven responses.

Advanced Security and Policy Enforcement

Security is integrated at every layer of the switch's operation:

Cisco TrustSec: Provides software-defined segmentation using Security Group Tags (SGTs). Policies follow users and devices, regardless of location, simplifying compliance and containment.
MACsec Encryption: IEEE 802.1AE encryption on all ports ensures data confidentiality and integrity on the wired LAN, protecting against eavesdropping and man-in-the-middle attacks.
Advanced Threat Protection: Integration with Cisco's Identity Services Engine (ISE) for context-aware network access control (NAA), and support for NetFlow for detailed visibility into application traffic patterns.

Deployment Scenarios and Ideal Use Cases

The versatility of the Cisco WS-C3850-24UW-S makes it suitable for a wide range of demanding enterprise environments.

Enterprise Campus and Branch Wiring Closets

As a premier access layer switch, it is the ideal termination point for end-users and devices in office buildings, corporate campuses, and remote branches. Its high PoE budget makes it perfect for power-dense areas like open-plan offices, conference rooms equipped with wireless collaboration systems, and classrooms.

High-Density Wireless Access Deployment

This is arguably its strongest use case. When deployed with a fleet of Cisco Aironet access points, the switch's Unified Access architecture allows it to terminate CAPWAP tunnels from the APs directly. This means wireless traffic can be forwarded and policies applied at the switch, offloading this processing from the Wireless LAN Controller (WLC) and creating a highly scalable, distributed wireless network.

Mid-Sized Data Center or Server Room Top-of-Rack (ToR)

With its four 10 Gigabit SFP+ uplinks and high switching capacity, the 3850 can serve as a cost-effective ToR switch for small to mid-sized server deployments, providing high-speed connectivity for physical and virtual servers.

IoT and Edge Networking Hub

The convergence of PoE+, robust security (TrustSec), and the ability to handle diverse traffic types makes the 3850 an excellent aggregation point for Internet of Things (IoT) deployments in smart buildings, healthcare (for medical device networks), and retail environments, where it can connect and power a heterogeneous mix of endpoints securely.

Embedded Event Manager (EEM) and Streaming Telemetry

For proactive operations, the Embedded Event Manager allows administrators to create custom scripts that trigger actions based on specific network events. Coupled with streaming telemetry, which provides a continuous, efficient stream of operational data (replacing SNMP pull), network teams can achieve real-time visibility and rapid problem detection.

Comparing the Catalyst 3850 in the Switching Portfolio

Understanding where the WS-C3850-24UW-S fits within Cisco's broader portfolio is key to making an informed selection.

vs. Catalyst 2960-X/XR Series

The Catalyst 2960-X is a capable Layer 2/3 Lite access switch but lacks the full Unified Access architecture, the stacking bandwidth of StackWise-480, and runs on traditional IOS. The 3850 is a more powerful, programmable, and wireless-converged successor.

vs. Catalyst 9300 Series

The Catalyst 9300 is the next-generation flagship access switch, featuring the more powerful UADP 2.0 ASIC, higher port densities, and enhanced programmability with always-on IOS XE. The 3850 is a previous-generation workhorse, offering exceptional value and performance, and represents a mature, battle-tested platform with a vast installed base. For many organizations, the 3850 provides the perfect balance of advanced features and cost-effectiveness.