C1-N3K-C3548X Cisco ONE Nexus 48 Ports Ethernet Switch

Product Overview

The Cisco C1-N3K-C3548X ONE Nexus 48-Port Ethernet Switch is a high-performance networking solution designed for modern data centers and enterprise environments. Built under the trusted Cisco Nexus portfolio, this switch delivers reliability, scalability, and ultra-fast connectivity for demanding workloads.

General Product Details

Manufacturer & Identification

• Brand: Cisco Systems, Inc.
• SKU / Part Number: C1-N3K-C3548X
• Product Line: Cisco Nexus
• Series: 3000 Series
• Model: 3548X
• Product Type: Layer 3 Ethernet Switch

Interface and Expansion Specifications

Port Configuration Overview

This Cisco Nexus switch is engineered with a modular architecture, enabling flexible deployment and future expansion to meet evolving network requirements.

Ports and Slots

• 48 × 10 Gigabit Ethernet ports for ultra-low latency connections
• 48 × SFP+ expansion slots for enhanced scalability
• No dedicated uplink ports in this configuration
• Stack ports are not included

Modular Design Benefits

• Supports adaptable network growth
• Allows easy upgrades and customization
• Optimized for data-intensive applications

Performance and Media Support

Networking Technology

The Cisco Nexus 3548X is optimized for high-speed data transmission and consistent performance in enterprise and cloud infrastructures.

• Supported Media: Optical fiber for stable, long-distance connectivity
• Ethernet Standard: 10 Gigabit Ethernet
• Network Technology: 10GBase-X for reliable, high-bandwidth communication

I/O Expansion Capabilities

Slot and Expansion Features

• Total of 48 available expansion slots
• SFP+ slot type for high-speed optical and copper connections
• Ideal for scalable and flexible network architectures

Network Layer Support and Management

Advanced Layer Capabilities

This Layer 3 switch supports advanced traffic handling and routing features, making it suitable for complex network environments.

• Supported Network Layer: Layer 4
• Manageability: Fully manageable with extensive configuration options
• Enhanced control for network optimization and monitoring

Architectural Foundation and Hardware Specifications

At its heart, the Cisco Nexus 3548X is built on a purpose-designed ASIC that provides consistent, predictable performance across all ports. This hardware-centric approach minimizes jitter and latency, which is non-negotiable for latency-sensitive applications.

Port Configuration and Density

The switch's primary configuration offers 48 fixed 1/10GBASE-T (copper RJ-45) ports, providing versatile connectivity for servers, storage, and other devices using standard Ethernet cabling. This high-density copper design is ideal for mainstream server connectivity where 10GbE over Cat6a/Cat7 is the standard.

Expansion Module Flexibility

A key differentiator is the inclusion of four Quad Small Form-Factor Pluggable (QSFP+) uplink ports. These ports are not fixed in function; each can operate as a native 40 Gigabit Ethernet interface or be broken out via a cable into four independent 10 Gigabit Ethernet interfaces. This flexibility allows network designers to tailor the switch's uplink capacity to the specific needs of the data center spine or core layer, supporting configurations of 4x40G, 16x10G, or a mixture thereof.

Performance and Buffering

With a total throughput of 1.44 Terabits per second and a forwarding rate of over 1 billion packets per second (bps), the 3548X handles traffic floods with ease. It is equipped with a deep packet buffer memory, a critical feature for preventing packet loss during microbursts common in east-west data center traffic and storage replication scenarios.

Advanced Software Features and Capabilities

Running Cisco NX-OS, a robust, mature, and highly stable operating system, the Nexus 3548X inherits a suite of enterprise-class features. NX-OS is built for availability, with fault-tolerant processes and hitless in-service software upgrades (ISSU) ensuring continuous operation.

Layer 2 and Layer 3 Functionality

The switch provides comprehensive Layer 2 switching protocols (VLAN, VTP, STP variants including Rapid-PVST+ and MST) and full Layer 3 IP routing. It supports static routing, OSPF, EIGRP, and BGP for dynamic routing, enabling it to function effectively as a leaf in a Clos-based spine-leaf architecture or in traditional multilayer designs.

Multicast Optimization

For financial services, media broadcasting, and collaborative applications, the switch offers advanced multicast features with hardware-based replication. Protocols like PIM Sparse Mode and SSM ensure efficient delivery of multicast streams without burdening the network.

Virtualization and Network Segmentation

In multi-tenant or secure environments, segmentation is paramount. The 3548X supports Virtual Routing and Forwarding (VRF) instances to create separate routing tables, and VLANs for Layer 2 isolation. For more granular policy enforcement, it integrates with Cisco TrustSec technology for group-based access control.

VXLAN Gateway Function

A significant capability is its function as a VXLAN (Virtual Extensible LAN) Layer 2 and Layer 3 gateway. VXLAN is an encapsulation protocol that creates overlay networks, enabling Layer 2 adjacency across a routed (Layer 3) underlay. This allows for the creation of scalable, flexible network segments that span physical boundaries, a foundation for modern cloud and software-defined networking (SDN).

Deployment Models and Use Cases

The versatility of the Cisco Nexus 3548X allows it to excel in several critical data center roles, adapting to the architectural paradigm in use.

Top-of-Rack (ToR) in Spine-Leaf Architecture

This is its most common and powerful deployment. As a leaf switch, each 3548X connects to a cluster of servers (via its 48x10G ports) and provides high-bandwidth, low-latency uplinks to the spine layer (using its QSFP+ ports). This design creates a non-blocking, predictable fabric ideal for east-west traffic.

Unified Fabric for Storage and Data

The switch supports Fibre Channel over Ethernet (FCoE) and FCoE Initialization Protocol (FIP) snooping, allowing for the consolidation of LAN and SAN traffic onto a single 10GbE wire. This reduces adapter count, cabling, and power/cooling requirements in the rack.

Middle-of-Row (MoR) or End-of-Row (EoR) Aggregation

For density-optimized deployments, the 3548X can serve as an aggregation switch for a row of racks. Its high port count and flexible uplinks make it suitable for consolidating traffic from multiple lower-speed access switches or servers before passing it to the core.

High-Frequency Trading (HFT) and Financial Networks

In HFT environments, latency is measured in nanoseconds. The switch's cut-through switching mode (where supported), combined with its low-latency ASIC and support for Precision Time Protocol (PTP), makes it a fixture in trading platforms where the fastest data transmission wins.

Management, Automation, and Programmability

Beyond the CLI, the Nexus 3548X offers a spectrum of management tools aligned with modern DevOps practices.

Cisco NX-API and Python Scripting

The embedded NX-API provides a RESTful API interface, allowing network operators to manage the switch using HTTP/HTTPS and JSON. This enables automation through Python, Ansible, or other orchestration tools, facilitating configuration management, bulk updates, and operational state checks.

Integration with Cisco ACI and DCNM

While a standalone device, the 3548X can be integrated into broader Cisco ecosystems. It can operate as a leaf node in an Application Centric Infrastructure (ACI) fabric under the control of an APIC controller. Alternatively, it can be managed centrally by the Cisco Data Center Network Manager (DCNM) for streamlined provisioning, monitoring, and lifecycle management across the Nexus portfolio.

Streaming Telemetry

Moving beyond traditional SNMP polling, the switch supports model-driven streaming telemetry. This allows it to push high-fidelity operational data (interface counters, buffer utilization, temperature) to collectors at regular intervals, enabling real-time network analytics and proactive troubleshooting.