Cisco QSFP-100G-SR4-S Compatible 100GBASE-SR4 QSFP28 850nm 100m OM4 DOM MPO-12 Parallel MMF Optical Transceiver Module, 4x 25G-SR

Overview

This module is a high-performance, parallel optical transceiver, providing a fully compatible alternative to the Cisco QSFP-100G-SR4-S. It is designed for short-reach 100 Gigabit Ethernet applications, delivering reliable connectivity up to 100 meters over OM4 multi-mode fiber (MMF). As an S-Class module, it is optimized for the cost and performance requirements of modern enterprise and data center environments.

The transceiver operates according to the 100GBASE-SR4 standard. It features four independent transmit and receive channels, each operating at 25Gbps for an aggregate data rate of 100Gbps. This parallel optics architecture, utilizing an MPO-12 connector, enables two primary modes of operation: a native 100G link between two transceivers or a 4x25G breakout connection, allowing a 100G switch port to connect to four separate 25G server or switch ports.

Key Features

• 100% compatible with Cisco platforms supporting the QSFP-100G-SR4-S module.
• Standard: Compliant with IEEE 802.3bm 100GBASE-SR4 and QSFP28 MSA.
• Dual Functionality: Supports native 100G and 4x25G breakout modes.
• Data Rate: 103.1 Gbps aggregate (4 x 25.78 Gbps).
• Reach: Supports up to 70m on OM3 MMF and 100m on OM4 MMF.
• Wavelength: 850nm VCSEL array.
• Connector: MPO-12/MTP-12.
• Built-in Digital Optical Monitoring (DOM/DDM) for real-time diagnostics.
• Hot-pluggable QSFP28 form factor.

Applications

The QSFP-100G-SR4-S compatible module is ideal for:

• High-density 100G data center and cloud network links.
• Switch-to-switch or switch-to-server interconnects.
• 100G to 4x25G fan-out for top-of-rack aggregation.
• High-performance computing (HPC) clusters.

Specifications

Cross-Platform Compatibility

Programmed for seamless integration with Cisco equipment, this module’s adherence to MSA standards ensures it can also be deployed in networking hardware from other major manufacturers that support 100GBASE-SR4 QSFP28 optics.

FAQ (Technical & Product Questions)

1. How does the 4x25G breakout mode work with the QSFP-100G-SR4-S?

Breakout mode is achieved using a specific type of cable. An MPO-to-4xLC breakout (or fan-out) cable connects to the MPO-12 port on the QSFP-100G-SR4-S and splits the four 25G lanes into four separate duplex LC connectors. These LC connectors can then be plugged into four individual SFP28 25G-SR transceivers on other devices.

2. What is the difference between QSFP-100G-SR4-S and QSFP-100G-LR4-S?

The key differences are reach, fiber type, and connector. SR4 (“Short Reach”) is for distances up to 100m using multi-mode fiber (MMF) and an MPO connector. LR4 (“Long Reach”) is for distances up to 10km using single-mode fiber (SMF) and a duplex LC connector. They are not interoperable.

3. What does the “-S” suffix on the part number mean?

The “-S” suffix designates the module as an S-Class optic within the Cisco portfolio. S-Class optics are intended for standard commercial temperature environments (0°C to 70°C) and are optimized for enterprise and data center use cases, often providing a more cost-effective option than industrial-grade modules.

4. What kind of fiber patch cable is required for a 100G link?

For a direct 100G connection between two QSFP-100G-SR4-S modules, you need a Type B (pinned-to-unpinned) MPO-12/MTP-12 female-to-female patch cable with OM3 or OM4 multi-mode fiber. OM4 is required to achieve the maximum 100m distance.

5. Is this module backward compatible with 40GBASE-SR4?

No. While the QSFP28 and QSFP+ form factors are physically the same, the electrical interfaces are different (4x25G vs 4x10G). A QSFP-100G-SR4-S module cannot operate at 40G speeds or connect to a 40GBASE-SR4 module.