Cisco QSFP-100G-SR1.2
100G SR1.2 BiDi QSFP Transceiver, LC, 100m OM4 MMF, Original Cisco
Product Highlights
Migrating your data center from 10G or 40G to 100G shouldn't mean ripping out your existing fiber plant. The Cisco QSFP-100G-SR1.2 is a 100G BiDi QSFP28 transceiver purpose-built to solve that exact problem — delivering 100 Gigabit Ethernet over the same duplex LC-connectorized multimode fiber you already have in place.
This pluggable optical module integrates four electrical data channels into two optical lanes using dual-wavelength VCSEL technology at 850 nm and 910 nm with PAM4 modulation, achieving an aggregate 100 Gbps link over a standard two-strand MMF connection. It supports link lengths of up to 70 m on OM3, 100 m on OM4, and 150 m on OM5 multimode fiber — covering the vast majority of intra-data-center distances.
Beyond the immediate 100G use case, the QSFP-100G-SR1.2 provides a clear upgrade path to 400G: it interoperates with the Cisco QDD-400G-SR4.2 in a 4×100G breakout mode, letting you scale spine-layer bandwidth without replacing leaf-layer optics. Built-in Digital Optical Monitoring (DOM) gives network operators real-time diagnostics, while full QSFP28 MSA compliance ensures broad platform compatibility across Cisco Nexus and Catalyst switching families. For data center architects who value infrastructure reuse and investment protection, the QSFP-100G-SR1.2 is the smart bridge between today's 100G needs and tomorrow's 400G ambitions.
Features & Benefits
BiDi Duplex LC Fiber Reuse
The QSFP-100G-SR1.2 uses bidirectional optics over a standard duplex LC connector, enabling 100G connectivity on the same two-strand multimode fiber used by 10G SFP+ and 40G BiDi deployments. This eliminates costly recabling projects and dramatically reduces migration time and expense when upgrading data center interconnects.
Dual-Wavelength PAM4 Optics
Each transceiver transmits and receives on two wavelengths in the 832–918 nm range, using PAM4 modulation to achieve 50 Gbps per optical lane. The four host-side electrical channels (4×25G NRZ) are multiplexed into two optical lanes, delivering a full 100 Gbps aggregate with high spectral efficiency and low power consumption.
400G Breakout Path
The QSFP-100G-SR1.2 is designed to interoperate with the Cisco QDD-400G-SR4.2 transceiver in a 4×100G breakout configuration. This means you can deploy 100G at the leaf layer today and upgrade the spine to 400G later — without touching the leaf optics or the fiber infrastructure.
Digital Optical Monitoring (DOM)
Real-time diagnostic data — including optical Tx/Rx power, laser bias current, module temperature, and supply voltage — is accessible via the standard I2C/QSFP28 MSA management interface. DOM enables proactive fault detection, simplifies troubleshooting, and supports automated monitoring through your existing NMS tools.
Hot-Pluggable QSFP28 Form Factor
The industry-standard QSFP28 form factor allows tool-free installation and removal without powering down the host device. This simplifies maintenance windows, accelerates deployments, and ensures compatibility with any platform that accepts QSFP28 modules.
Deployment Scenarios
Data Center Leaf-Spine 100G Fabric
Deploy the QSFP-100G-SR1.2 at the leaf layer to deliver 100G uplinks to spine switches over existing duplex MMF cabling. As bandwidth demands grow, upgrade the spine to 400G using QDD-400G-SR4.2 in breakout mode without replacing leaf-side optics or fiber.
10G/40G to 100G Migration
Organizations running 10G SFP+ or 40G BiDi over duplex LC multimode fiber can upgrade to 100G by simply swapping transceivers — no fiber re-pull required. This dramatically reduces migration cost and downtime for campus or data center environments.
Top-of-Rack Server Connectivity
Use the QSFP-100G-SR1.2 in top-of-rack switches to provide 100G links to servers or storage arrays within the same row or adjacent racks. The 100 m OM4 reach covers typical intra-pod distances with margin to spare.
High-Performance Computing Interconnects
HPC clusters requiring low-latency, high-bandwidth node-to-node connectivity benefit from the QSFP-100G-SR1.2's 100 Gbps throughput over short-reach multimode fiber, keeping cabling simple and cost-effective across dense compute environments.
General
Performance
Reach
Power & Environmental
Compliance
Compatibility Notes
The Cisco QSFP-100G-SR1.2 is supported on Cisco Nexus 9300 series platforms. Per the Cisco optics compatibility matrix, NX-OS 9.3(9) with SMU may be required for certain Nexus 9300 models (e.g., N9K-C9336C-FX2). Always verify compatibility for your specific platform and software version using the Cisco Transceiver Module Group (TMG) Compatibility Matrix. The transceiver uses a duplex LC connector and requires OM3, OM4, or OM5 multimode fiber. It interoperates with another QSFP-100G-SR1.2 for 100G point-to-point links, or with the QDD-400G-SR4.2 in 4×100G breakout mode.
Downloads & Resources
Frequently Asked Questions
| Part Number | Product | Key Difference |
|---|---|---|
| QSFP-40/100-SRBD | Cisco 40/100G SR-BiDi QSFP Transceiver | Dual-rate 40G/100G BiDi over duplex LC; choose this if you need backward compatibility with 40G BiDi links |
| QSFP-100G-SR4-S | Cisco 100GBASE-SR4 QSFP28 Transceiver | Uses 4 parallel lanes over 8-fiber MPO/MTP connector; higher density but requires parallel MMF infrastructure |
| QDD-400G-SR4.2 | Cisco 400G SR4.2 BiDi QSFP-DD Transceiver | 400G BiDi over duplex MMF; supports 4×100G breakout to QSFP-100G-SR1.2 for spine-leaf architectures |
| QSFP-100G-SR-S | Cisco 100GBASE-SR QSFP28 Transceiver (S-Class) | Single-lane 100G SR over one MMF strand with PAM4; requires OM4/OM5 but uses simplex fiber per direction |
