QSFP-40/100-SRBD is a Cisco QSFP transceiver designed for short-reach, high-speed fiber links. It’s a dual-rate 40GbE / 100GbE BiDi (bidirectional) module that runs over standard duplex multimode fiber, allowing bandwidth upgrades without replacing existing OM3/OM4 cabling.
Why buyers pick QSFP-40/100-SRBD (plain English)
Reuse existing fiber for 100G Delivers 40G or 100G over the same duplex multimode fiber used for 10G/40G links.
Simple migration path Supports both 40GbE and 100GbE, making it ideal for phased network upgrades.
BiDi efficiency Uses two wavelengths over two fibers instead of 8 or 20 fibers, reducing cabling complexity.
Short-reach, high density Perfect for data centers and wiring closets where distances are limited but port density matters.
Cisco-qualified optics Designed for compatibility and reliability in Cisco switching platforms.
60-second spec box (QSFP-40/100-SRBD)
Form factor QSFP
Speed 40GbE / 100GbE (dual-rate)
Fiber type Multimode fiber (OM3 / OM4)
Wavelength 850 nm / 900 nm (BiDi)
Connector LC duplex
Max distance Up to ~100 m (OM3) Up to ~150 m (OM4)
Use case Data center short-reach links and 40G→100G fiber reuse.
Where it fits (and when to choose something else)
Perfect for:
Data centers upgrading from 40G to 100G
Environments reusing existing multimode fiber
High-density short-reach switch interconnects
Choose something else if:
You’re using single-mode fiber → choose LR optics
You need longer distances → LR or ER modules
You’re building new fiber runs → standard SR4 may be preferred
TL;DR
QSFP-40/100-SRBD is Cisco’s dual-rate 40G/100G BiDi QSFP optic: a short-reach transceiver that enables high-speed upgrades over existing duplex multimode fiber.
Key specifications
Feature
Specification
Source
Form Factor
QSFP+ for 40G, QSFP28 for 100G
Data Rate
Dual-rate: 40 Gbps and 100 Gbps
Interface
SR-BiDi
Media Type
Multimode Fiber (MMF)
Connector
Duplex LC
Wavelength
855nm and 908nm (dual-wavelength)
Maximum Distance
40 Gbps: 100m (OM3), 150m (OM4); 100 Gbps: 70m (OM3), 100m (OM4)
Operating Temperature
100G: 10°C to 60°C; 40G: 10°C to 70°C
Digital Optical Monitoring
Yes (DOM/DDM)
Power Consumption
< 3.5 Watts
Key Technology
Bi-Directional (BiDi) transmission over two fibers
Features and applications
Dual-Rate Functionality: Allows for an upgrade path from 40G to 100G without needing to replace the fiber infrastructure.
Cost-Effective Migration: Reuses existing duplex MMF cabling, making it a budget-friendly option for data center upgrades.
High Performance: Supports high-speed, short-reach data communication within data centers for server-to-switch and switch-to-switch interconnects.
BiDi Technology: Transmits and receives data on different wavelengths over the same fiber strands, maximizing fiber utilization.
Hot-Swappable: Can be installed or removed without interrupting network services.
