WS-C3850-12X48U-L Cisco Catalyst 3850 Managed Switch, 48 Ports

Product Overview

The Cisco WS-C3850-12X48U-L Catalyst 3850 is a high-performance, enterprise-grade managed switch designed for modern networks that demand speed, scalability, and advanced Layer 3 functionality. Built with Cisco reliability, this switch is ideal for campus, branch, and mid-size business environments.

General Specifications

• Brand: Cisco
• Model Number: WS-C3850-12X48U-L
• Device Category: Managed Layer 3 Ethernet Switch
• Total Ports: 48 Ethernet Ports
• Form Factor: Desktop and 1U Rack-Mountable
• Stackable Design: Yes
• Network Subtype: Gigabit Ethernet

Port Configuration & Power Capabilities

Ethernet Ports

• 48 x 10/100/1000 Mbps Ethernet ports
• Supports Universal Power over Ethernet (UPOE)

Power over Ethernet

• PoE Technology: UPOE
• Total PoE Power Budget: 630 Watts
• Ideal for IP phones, wireless access points, and IoT devices

Performance & Switching Capacity

High-Speed Performance

• Switching Capacity: 176 Gbps
• Stacking Bandwidth: 480 Gbps
• Forwarding Rate: 460 Mpps (64-byte packets)

Network Capacity & Scalability

• IPv4 Routing Entries: Up to 24,000
• NetFlow Records: 48,000 entries
• Switched Virtual Interfaces (SVIs): 1,000
• MAC Address Table: 32,000 entries
• Jumbo Frame Support: Up to 9,198 bytes

Routing & Management Protocols

Supported Routing Protocols

• RIP v1 & v2
• RIPng
• EIGRP

Advanced Network Features

Security & Control

• Access Control Lists (ACL)
• Dynamic ARP Inspection (DAI)
• DHCP Snooping
• STP Root Guard and UDLD
• RADIUS authentication support

Traffic Optimization & Reliability

• Quality of Service (QoS)
• Link Aggregation (LACP & PAgP)
• VLAN and Trunking support
• IGMP and MLD Snooping
• Rapid Spanning Tree (RSTP), MSTP, and PVST+

Cisco-exclusive technologies enhance uptime and efficiency.

• Cisco StackWise-480 Technology
• Cisco StackPower Technology
• Flexible NetFlow (FNF)
• Energy Efficient Ethernet

Standards & Compliance

Industry Certifications

• IEEE 802.3, 802.3u, 802.3z
• IEEE 802.1Q, 802.1D, 802.1P
• IEEE 802.3af & 802.3at (PoE)
• IEEE 802.1X, 802.1W, 802.1S
• IEEE 802.3ad (LACP)

Power & Redundancy

• Power Input: AC 120/230V, 50/60 Hz
• Redundant Power Support: Optional

Unified Access Architecture: A Paradigm Shift

At the heart of the Catalyst 3850 is Cisco's Unified Access Data Plane (UADP) application-specific integrated circuit (ASIC). This innovative technology allows the switch to function not just as a traditional wired switch but also as a high-performance Wireless LAN Controller (WLC). This convergence eliminates the need for separate overlay networks, reducing complexity, latency, and operational overhead. Network administrators gain a single point of management and policy enforcement for all connected devices, whether they join via an Ethernet cable or a Wi-Fi access point.

Deep Dive: Cisco WS-C3850-12X48U-L Hardware Specifications

The Cisco WS-C3850-12X48U-L is a 1RU (rack unit) stackable managed switch designed for high-density access deployments. Its hardware configuration is tailored for environments requiring Power over Ethernet (PoE), high-speed uplinks, and flexible expansion.

Port Configuration and Power Capabilities

This model features a sophisticated port arrangement designed for maximum utility:

Downlink Ports

48 x 10/100/1000BASE-T Ethernet Ports: All forty-eight copper ports support Gigabit Ethernet speeds and are equipped with Cisco Universal PoE+ (UPoE) capability. UPoE can deliver up to 60 watts of power per port, supporting a vast array of devices beyond standard phones and access points, including advanced systems like telepresence endpoints, point-of-sale systems, and building management controllers.

Uplink and Expansion Ports

12 x 1G/10G SFP+ Uplink Ports: These ports offer unparalleled uplink flexibility. They can operate as 1 Gigabit Ethernet or 10 Gigabit Ethernet fiber ports using the appropriate SFP/SFP+ modules, providing ample bandwidth for aggregation and backbone connectivity.

Stacking Capabilities: The switch includes dedicated stack ports using Cisco StackWise-480 technology. This allows you to logically combine up to 9 physical switches into a single, resilient switching unit with a 480 Gbps stacking backplane, creating a simplified, highly available network domain.

Performance and Switching Capacity

Built for performance, the WS-C3850-12X48U-L delivers non-blocking switching across all ports. With a forwarding rate of up to 176 Gbps and a switching capacity of 480 Gbps (with StackWise), it ensures line-rate traffic flow even in bandwidth-intensive applications. Its deep buffers help prevent packet loss during traffic bursts, crucial for data center edge or high-performance computing access scenarios.

Advanced Software Features and Capabilities

Running Cisco IOS XE, a modern, modular operating system, the Catalyst 3850 unlocks a comprehensive suite of enterprise-grade features.

Network Foundation and Intelligence

Cisco StackWise-480 Technology

More than just stacking, StackWise-480 creates a single, logical switch from multiple physical units. It provides:

Simplified Management: The entire stack is managed as one entity via a single IP address.

High Resiliency: Stateful switchover (SSO) and hitless software upgrades ensure network continuity.

Flexible Scalability: Add capacity incrementally as network needs grow.

Application Visibility and Control (AVC)

Integrating Cisco's NBAR2 (Next-Generation Network-Based Application Recognition), the switch provides deep packet inspection to classify and control over 1400 applications. This allows for the creation of intelligent QoS policies, ensuring mission-critical applications like voice and video receive priority, while limiting or shaping less important traffic.

Comprehensive Security Suite

Security is embedded at every layer of the switch's functionality.

TrustSec Technology

Cisco TrustSec uses Software-Defined Access (SDA) principles to enforce security policies based on user and device identity, not just IP addresses. It employs Security Group Tags (SGTs) to classify traffic, enabling scalable segmentation and containment of security breaches.

Advanced Threat Protection

Cisco Identity Services Engine (ISE) Integration: For centralized policy enforcement, profiling, and BYOD management.

MACsec Encryption: Provides hop-by-hop IEEE 802.1AE encryption on selected ports, securing data traversing the switch fabric.

Dynamic ARP Inspection & IP Source Guard: Protect against layer 2 spoofing attacks.

Deployment Use Cases and Scenarios

The versatility of the WS-C3850-12X48U-L makes it suitable for a wide range of enterprise and specialized environments.

High-Density Unified Access Deployment

In large office campuses or educational institutions, this switch is ideal. Its 48 UPoE ports can power a dense deployment of Cisco Aironet access points, phones, and IoT sensors, while its built-in WLC functionality (when licensed) manages thousands of wireless clients seamlessly. The 10G SFP+ uplinks provide ample bandwidth back to the core.

IoT and Digital Building Convergence

With Universal PoE, the switch can power and connect a diverse ecosystem of building systems—lighting, HVAC, security cameras, digital signage, and access control systems. Its robust security features allow for the segmentation of these IoT devices onto separate, policy-controlled networks, mitigating risk.

Medium Data Center or Server Access Layer

For medium-sized data centers or as a top-of-rack switch, its high 10G density, low latency, and support for data center bridging (DCB) protocols make it a reliable choice for server and storage connectivity.

Comparison and Considerations

Within the Catalyst 3850 Family

The "L" in WS-C3850-12X48U-L denotes the Network Advantage license. It is crucial to compare this with the "S" model (Network Essentials). For organizations requiring advanced routing, full security features, and programmability, the "-L" variant is the necessary and more capable choice.

Successor and Complementary Products

While the Catalyst 3850 remains a highly capable and widely deployed platform, Cisco's Catalyst 9000 Series (e.g., C9300, C9400) is its strategic successor, built on a more modern ASIC architecture and designed explicitly for software-defined access with mandatory DNA capabilities. The 3850 is often considered for stable, feature-rich traditional deployments or as a cost-effective high-PoE density option, while the Catalyst 9000 is chosen for greenfield SD-Access deployments and longer-term roadmap alignment.