What is the Difference Between 400G-BIDI, 400G-SRBD and 400G-SR4.2?

Picture of John Doe

John Doe

Answered on 7:51 am

The difference between 400G-BIDI, 400G-SRBD and 400G-SR4.2 is mainly in the naming convention and the form factor of the modules. They are all based on the same principle of using four pairs of multimode fibers, each carrying two wavelengths of 25G signals in both directions, for a total of 400G bandwidth. The term 400G-BIDI is a generic name for this technology, while 400G-SRBD and 400G-SR4.2 are specific names for the modules that implement it.

The 400G-SRBD module is based on the QSFP-DD form factor, which is a double-density version of the QSFP form factor. It has an MPO-12 connector that can be plugged into an existing QSFP port. The 400G-SRBD module can also be used for breakout applications, where it can be connected to four 100G-BIDI modules that use the QSFP28 form factor.

The 400G-SR4.2 module is based on the OSFP form factor, which is a new form factor designed for higher power and thermal performance. It has an MPO-16 connector that can support higher fiber counts and longer distances. The 400G-SR4.2 module can also be used for breakout applications, where it can be connected to four 100G-SR1.2 modules that use the SFP-DD form factor.

Both the 400G-SRBD and the 400G-SR4.2 modules are compliant with the IEEE 802.3bm protocol and the 400G BiDi MSA specification. They can support link lengths of up to 100m over OM4 multimode fiber.

People Also Ask

NVIDIA GB200 NVL72: Defining the New Benchmark for Rack-Scale AI Computing

The explosive growth of Large Language Models (LLM) and Mixture-of-Experts (MoE) architectures is fundamentally reshaping the underlying logic of computing infrastructure. As model parameters cross the trillion mark, traditional cluster architectures—centered on standalone servers connected by standard networking—are hitting physical and economic ceilings. In this context, NVIDIA’s GB200 NVL72 is

In-Depth Analysis Report on 800G Switches: Architectural Evolution, Market Landscape, and Future Outlook

Introduction: Reconstructing Network Infrastructure in the AI Era Paradigm Shift from Cloud Computing to AI Factories       Global data center networks are undergoing the most profound transformation in the past decade. Previously, network architectures were primarily designed around cloud computing and internet application traffic patterns, dominated by “north-south” client-server models. However,

Global 400G Ethernet Switch Market and Technical Architecture In-depth Research Report: AI-Driven Network Restructuring and Ecosystem Evolution 

Executive Summary Driven by the explosive growth of the digital economy and Artificial Intelligence (AI) technologies, global data center network infrastructure is at a critical historical node of migration from 100G to 400G/800G. As Large Language Model (LLM) parameters break through the trillion level and demands for High-Performance Computing (HPC)

Key Design Constraints for Stack-OSFP Optical Transceiver Cold Plate Liquid Cooling

Foreword  The data center industry has already adopted 800G/1.6T optical modules on a large scale, and the demand for cold plate liquid cooling of optical modules has increased significantly. To meet this industry demand, OSFP-MSA V5.22 version has added solutions applicable to cold plate liquid cooling. At present, there are

NVIDIA DGX Spark Quick Start Guide: Your Personal AI Supercomputer on the Desk

NVIDIA DGX Spark — the world’s smallest AI supercomputer powered by the NVIDIA GB10 Grace Blackwell Superchip — brings data-center-class AI performance to your desktop. With up to 1 PFLOP of FP4 AI compute and 128 GB of unified memory, it enables local inference on models up to 200 billion parameters and fine-tuning of models

Related Articles

800g sr8 and 400g sr4

800G SR8 and 400G SR4 Optical Transceiver Modules Compatibility and Interconnection Test Report

Version Change Log Writer V0 Sample Test Cassie Test Purpose Test Objects:800G OSFP SR8/400G OSFP SR4/400G Q112 SR4. By conducting corresponding tests, the test parameters meet the relevant industry standards, and the test modules can be normally used for Nvidia (Mellanox) MQM9790 switch, Nvidia (Mellanox) ConnectX-7 network card and Nvidia (Mellanox) BlueField-3, laying a foundation for

Read More »
nvidia

NVIDIA GB200 NVL72: Defining the New Benchmark for Rack-Scale AI Computing

The explosive growth of Large Language Models (LLM) and Mixture-of-Experts (MoE) architectures is fundamentally reshaping the underlying logic of computing infrastructure. As model parameters cross the trillion mark, traditional cluster architectures—centered on standalone servers connected by standard networking—are hitting physical and economic ceilings. In this context, NVIDIA’s GB200 NVL72 is

Read More »
Report on 800G Switches

In-Depth Analysis Report on 800G Switches: Architectural Evolution, Market Landscape, and Future Outlook

Introduction: Reconstructing Network Infrastructure in the AI Era Paradigm Shift from Cloud Computing to AI Factories       Global data center networks are undergoing the most profound transformation in the past decade. Previously, network architectures were primarily designed around cloud computing and internet application traffic patterns, dominated by “north-south” client-server models. However,

Read More »
400G global market

Global 400G Ethernet Switch Market and Technical Architecture In-depth Research Report: AI-Driven Network Restructuring and Ecosystem Evolution 

Executive Summary Driven by the explosive growth of the digital economy and Artificial Intelligence (AI) technologies, global data center network infrastructure is at a critical historical node of migration from 100G to 400G/800G. As Large Language Model (LLM) parameters break through the trillion level and demands for High-Performance Computing (HPC)

Read More »
Scroll to Top