Comprehensive Product Overview

The Cisco QSFP-100G-ER4L-S is a hot-pluggable, standards-compliant 100 Gigabit Ethernet optical transceiver module designed for long-reach, high-density networking applications. Built on the QSFP28 form factor, it leverages four CWDM optical lanes (1295nm, 1300nm, 1304nm, 1309nm) to transmit 100Gbps traffic across standard G.652 single-mode fiber (SMF).

This module supports 100GBASE-ER4 Lite operation, providing a reach of 40km with host FEC and 30km without FEC, making it a cost-effective solution for extending 100G connectivity beyond traditional 10km LR4 limits. It features integrated Digital Optical Monitoring (DOM) for real-time performance diagnostics and is fully compatible with Cisco’s portfolio of 100G switches and routers.

Key Features & Business Benefits

Technical Specifications

Ideal Application Scenarios

• Data Center Interconnect (DCI) – High-speed 100G links between geographically dispersed data centers (up to 40km).
• Metro & Regional Backbone Networks – Service provider 100G transport for 5G, cloud, and enterprise services.
• Enterprise WAN & Campus Backbone – Long-distance 100G connectivity for large campus networks and multi-site enterprises.
• High-Performance Computing (HPC) – Low-latency 100G links for AI/ML training clusters and supercomputing environments.
• Financial & Healthcare Networks – Secure, reliable 100G connections for latency-sensitive and mission-critical applications.

Supported Accessories & Modules

• Single-Mode Fiber Patch Cables – Duplex LC-LC OS2 SMF cables (9/125µm) for 40km links.
• Fiber Management Panels – LC adapter panels and patch panels for organized cable routing.
• Cisco 100G Switches/Routers – Fully supported on Cisco Nexus 9000, Catalyst 9000, and ASR 1000 series with QSFP28 ports.
• Optical Attenuators – For power balancing in high-power link setups.
• Cleaning Kits – LC connector cleaning tools for maintaining optimal optical performance.

Frequently Asked Questions (FAQ)

Q: What is the difference between QSFP-100G-ER4L-S and QSFP-100G-LR4-S?

A: The QSFP-100G-LR4-S supports up to 10km over SMF, while the QSFP-100G-ER4L-S extends reach to 40km (with FEC) using the same 1310nm CWDM wavelengths, making it ideal for longer-distance 100G deployments.

Q: Does the QSFP-100G-ER4L-S require FEC for 40km operation?

A: Yes. The module achieves 40km only when used with a host device that supports Forward Error Correction (FEC). Without FEC, the maximum reach is 30km.

Q: Is this module compatible with non-Cisco 100G switches?

A: The QSFP-100G-ER4L-S complies with IEEE 802.3bm and QSFP28 MSA standards, ensuring basic interoperability with third-party 100GBASE-ER4 Lite equipment. For full feature support (e.g., DOM), Cisco-based systems are recommended.

Q: What is the power consumption of the QSFP-100G-ER4L-S?

A: The module has a maximum power draw of 4.5W, making it energy-efficient for high-density 100G port deployments.

Q: Can I use this module with multimode fiber (MMF)?

A: No. The QSFP-100G-ER4L-S is designed exclusively for single-mode fiber (SMF). Using MMF will result in signal degradation and no link establishment.

Q: Does the module support Digital Optical Monitoring (DOM)?

A: Yes. It provides real-time monitoring of optical transmit power, receive power, temperature, and supply voltage via the I2C interface, enabling proactive network maintenance.