会社のニュース Cisco QSFP-40G-SR4 40G Optical Transceiver Module for High-Speed Data Center Connectivity

Cisco QSFP-40G-SR4 optical transceiver module is a 40GBASE-SR4 multimode fiber solution designed for high-speed data center interconnects and enterprise network switching. It delivers stable 40Gbps transmission performance using MPO/MTP interface technology and 850nm VCSEL optical design. This Cisco QSFP-40G-SR4 module supports short-range communication up to 150 meters over OM4 fiber, making it ideal for cloud infrastructure, enterprise backbone networks, and high-density switch deployments.

As network bandwidth demand continues to grow rapidly in modern IT environments, the Cisco QSFP-40G-SR4 provides a cost-efficient and scalable upgrade path from 10G to 40G Ethernet architecture. Its low power consumption, hot-swappable QSFP+ form factor, and full compliance with IEEE 802.3ba standards ensure reliable interoperability across Cisco Nexus, Catalyst, and other enterprise-grade switching platforms.

The Cisco QSFP-40G-SR4 is a Quad Small Form-Factor Pluggable Plus (QSFP+) optical transceiver designed for parallel optical transmission over multimode fiber (MMF). It operates at a central wavelength of 850nm and utilizes Vertical Cavity Surface Emitting Laser (VCSEL) technology to achieve high-speed optical signal modulation across four independent transmission lanes.

Each lane supports 10Gbps data transmission, combining to deliver an aggregate throughput of 40Gbps full-duplex communication. The module uses an MPO/MTP-12 optical connector interface, which distributes optical signals across eight fiber strands (four transmit and four receive channels) in a parallel optical architecture.

The physical structure follows QSFP+ Multi-Source Agreement (MSA) standards, ensuring mechanical compatibility and electrical interoperability with compliant switch ports. The module is designed for multimode fiber types such as OM3 and OM4, where modal dispersion characteristics allow for short-reach high-bandwidth transmission. Its optical budget is optimized for distances up to 100 meters on OM3 and 150 meters on OM4 fiber infrastructure.

In engineering terms, the SR4 architecture represents a short-reach parallel optics solution where electrical 10G SerDes lanes are converted into optical signals via VCSEL arrays, minimizing latency and maximizing port density in data center switching environments.

Modern data centers face increasing pressure to support higher bandwidth, lower latency, and more scalable network architectures. Traditional 10G infrastructures are no longer sufficient for virtualization workloads, cloud computing, and AI-driven applications. The Cisco QSFP-40G-SR4 directly addresses these challenges by enabling a seamless transition to 40G Ethernet.

One of the key advantages is high-density port efficiency, allowing four 10G connections to be consolidated into a single 40G uplink. This reduces switch port congestion and improves overall rack utilization. Another major benefit is cost-effective multimode fiber reuse, where existing OM3/OM4 cabling infrastructure can be leveraged without expensive rewiring.

From a procurement perspective, the Cisco QSFP-40G-SR4 offers strong interoperability with Cisco QSFP+ modules, including compatibility with Cisco Nexus 3000/5000/7000 series and Catalyst 9000 platforms. This reduces integration risk and ensures predictable deployment performance.

Additional advantages include low power optical transmission design (<1.5W typical), which reduces operational energy costs in large-scale deployments, and hot-swappable QSFP+ architecture, which minimizes downtime during maintenance. Compared with QSFP-40G-LR4 single-mode solutions or QSFP-40G-SR-BD duplex LC alternatives, the SR4 model provides a superior balance between cost, density, and deployment flexibility for short-range interconnects.

In real-world deployment scenarios, the Cisco QSFP-40G-SR4 is widely used in spine-leaf data center architectures, where high-throughput inter-switch connectivity is required. In a typical enterprise environment, leaf switches aggregate server traffic at 10G or 25G per port, while spine switches utilize 40G SR4 uplinks to ensure non-blocking bandwidth distribution.

For example, in a 40G aggregation layer built on Cisco Nexus switches, each QSFP-40G-SR4 module connects via MPO/MTP-12 trunk cables over OM4 multimode fiber. The optical link supports up to 150 meters, which is sufficient for most intra-data-center rack-to-rack or row-to-row connections. The 4×10G breakout capability also allows engineers to split one 40G port into four independent 10G links using MPO-to-LC breakout cables, enabling flexible network segmentation.

From a technical configuration perspective, the module operates with VCSEL-based 850nm transmitters aligned in parallel lanes, requiring precise fiber polarity management (Type-B MPO cabling recommended). Optical insertion loss is tightly controlled within IEEE 802.3ba standards to maintain signal integrity across all four channels.

In cloud infrastructure environments, such as virtualization clusters and storage networks, QSFP-40G-SR4 modules are deployed to connect high-performance compute nodes with aggregation switches, ensuring consistent low-latency traffic flow. The module’s DOM (Digital Optical Monitoring) feature allows network engineers to monitor real-time parameters such as optical power, temperature, and bias current, enabling proactive maintenance and reducing network downtime.

In addition, telecom operators and enterprise IT departments often deploy SR4 modules in modular switch chassis environments where port density and airflow optimization are critical. Because the module is hot-swappable, maintenance operations can be performed without disrupting live traffic, which is essential for mission-critical applications.

Cisco QSFP-40G-SR4 is used for 40Gbps short-range optical transmission in data center networks. It connects switches, servers, and storage devices over multimode fiber, providing stable high-speed backbone connectivity for enterprise and cloud environments.

This module supports multimode fiber (MMF), specifically OM3 and OM4 fiber types. It uses MPO/MTP-12 connectors to enable parallel optical transmission across multiple lanes for high bandwidth performance.

The QSFP-40G-SR4 supports up to 100 meters on OM3 fiber and up to 150 meters on OM4 fiber under standard operating conditions, making it ideal for intra–data center connections.

Yes, it is fully compatible with Cisco QSFP+ 40G ports, including Cisco Nexus, Catalyst, and ASR series switches. It ensures plug-and-play operation in supported hardware platforms.

Yes, it supports 40G to 4×10G breakout configurations using MPO breakout cables. This allows network engineers to split one 40G port into four independent 10G links for flexible network design.

The module typically consumes less than 1.5W of power, making it energy-efficient and suitable for high-density data center deployments where power and cooling efficiency are critical.

The Cisco QSFP-40G-SR4 optical transceiver module delivers a highly efficient, scalable, and cost-effective solution for modern 40G Ethernet networks. With strong compatibility, low power consumption, and flexible deployment options, it remains a preferred choice for enterprise and cloud data center infrastructure.