747698-B21 HPE 40GBASE-SR4 QSFP+ Module - 40GBE MMF Transceiver

Overview of HPE 747698-B21 QSFP+ Optical Transceiver

The HPE 747698-B21 QSFP+ module is a high-speed fiber optic transceiver designed for 40 Gigabit Ethernet connectivity. Supporting multi-mode fiber with MPO interfaces, it ensures efficient short-range transmission, making it ideal for enterprise and data center networking environments.

General Information

• Manufacturer: HPE 
• Part Number: 747698-B21
• Category: QSFP+ Transceiver Module

Technical Specifications

Form Factor & Interface

• Form Factor: Plug-in module
• Interface: 1 x Ethernet 40GBASE-SR4 with MPO multi-mode connector

Networking Features

• Connectivity Technology: Wired
• Cabling Type: 40GBASE-SR4
• Data Link Protocol: 40 Gigabit Ethernet
• Data Transfer Rate: 40 Gbps
• Optical Wavelength: 850 nm
• Maximum Transfer Distance: 984 ft (approx. 300 meters)
• Compliant Standards: IEEE 802.3ba

HPE 747698-B21 Compatible 40GBASE-SR4 QSFP+ Module

Understanding the Role of HPE 747698-B21 Compatible Optical Transceiver

The HPE 747698-B21 Compatible 40GBASE-SR4 QSFP+ Module is a high-performance multi-mode fiber optic transceiver designed to deliver reliable 40 Gigabit Ethernet connectivity across modern data center environments. This optical module is engineered as a cost-effective alternative to original branded transceivers while maintaining full compatibility with HPE networking hardware ecosystems. It plays a crucial role in high-speed data transmission environments where bandwidth density, low latency, and stable optical performance are essential for enterprise-grade infrastructure.

As a QSFP+ (Quad Small Form-factor Pluggable Plus) module, this device integrates four independent transmit and receive channels, each operating at 10Gbps, collectively achieving a total aggregated bandwidth of 40Gbps. The module adheres to the IEEE 802.3ba 40GBASE-SR4 standard, ensuring interoperability with a wide range of switches, routers, and network interface cards in high-density networking architectures.

Position in Modern Networking Architecture

Within contemporary data center topologies, the HPE 747698-B21 compatible module is widely deployed in spine-leaf architectures, cloud data centers, virtualization clusters, and high-performance computing environments. It supports short-range optical communication over multi-mode fiber, typically enabling efficient rack-to-rack or intra-rack interconnectivity. Its design aligns with the growing demand for scalable bandwidth, especially in environments driven by cloud computing, big data analytics, and virtualization workloads.

Technical Architecture of 40GBASE-SR4 QSFP+ Module

Parallel Optical Transmission Design

The 40GBASE-SR4 architecture is based on parallel optical transmission technology. Instead of relying on a single high-speed channel, the module divides data into four separate lanes, each transmitting at 10Gbps. These lanes operate simultaneously, ensuring consistent throughput and reduced signal degradation over short distances. This parallel design significantly improves efficiency in data centers where high-density traffic is common.

Multi-Lane Data Encoding

Each lane within the QSFP+ module uses advanced encoding techniques to maintain signal integrity. The encoding mechanism ensures minimal bit error rates, enabling stable communication even under heavy network load conditions. The synchronization of these lanes is critical to achieving the full 40Gbps throughput without packet loss or timing discrepancies.

Multi-mode Fiber Optical Behavior

The module operates over multi-mode fiber (MMF), typically OM3 or OM4-grade fiber cabling. Multi-mode fiber supports multiple light propagation paths, allowing efficient short-distance transmission. This makes the module ideal for data center interconnects rather than long-haul telecommunications. The SR4 standard typically supports distances up to 100 meters on OM3 fiber and up to 150 meters on OM4 fiber under optimal conditions.

Optical Components and Signal Processing

Inside the transceiver, vertical-cavity surface-emitting lasers (VCSELs) are commonly used as the light source. These lasers are optimized for multi-mode fiber transmission, offering high efficiency and low power consumption. The receiving end uses photodiodes capable of detecting high-speed optical signals and converting them into electrical signals for processing by network equipment.

Compatibility and Interoperability

HPE Networking Ecosystem Integration

The HPE 747698-B21 compatible QSFP+ module is designed to operate seamlessly with a wide range of HPE ProCurve, HPE Aruba, and HPE FlexNetwork switches. Its firmware and encoding profiles are tuned to ensure that the module is recognized correctly by host devices, enabling plug-and-play installation in supported QSFP+ ports.

Standards-Based Interoperability

Compliance with IEEE 802.3ba ensures that the module can interoperate with other standard-compliant 40GBASE-SR4 devices from different manufacturers. This flexibility is especially beneficial in heterogeneous network environments where equipment from multiple vendors coexists. The module’s adherence to industry standards helps reduce vendor lock-in while maintaining performance consistency.

Firmware and Digital Diagnostics Monitoring

Many compatible QSFP+ modules, including this model, support Digital Diagnostics Monitoring (DDM) functions. DDM allows real-time monitoring of parameters such as temperature, optical power, voltage, and laser bias current. This capability enhances network visibility and enables proactive maintenance strategies to minimize downtime.

Performance Characteristics of 40GBASE-SR4 QSFP+ Module

High-Speed Data Throughput

The primary advantage of the HPE 747698-B21 compatible module lies in its 40Gbps data throughput capability. This high bandwidth capacity supports demanding applications such as virtualization clusters, storage area networks, and high-performance computing workloads. The aggregated parallel transmission structure ensures consistent performance even during peak traffic conditions.

Low Latency Transmission

Latency is a critical factor in modern networking, especially in financial trading systems, real-time analytics, and cloud computing environments. The SR4 QSFP+ module is engineered to minimize transmission delay by optimizing optical-to-electrical conversion processes and reducing internal signal processing overhead.

Distance Limitations and Optimal Deployment Scenarios

The module is optimized for short-range communication. Its effective range depends on the type of multi-mode fiber used. OM3 fiber supports distances up to approximately 100 meters, while OM4 fiber extends performance up to around 150 meters. This makes it ideal for intra-data center connectivity rather than metropolitan or wide-area deployments.

Fiber Optic Cabling

Importance of OM3 and OM4 Multi-mode Fiber

To achieve optimal performance, the HPE 747698-B21 compatible QSFP+ module requires high-quality multi-mode fiber cabling. OM3 fiber supports laser-optimized transmission and is suitable for most standard deployments. OM4 fiber, with improved modal bandwidth, enables longer transmission distances and better overall signal quality.

Connector Type and Physical Interface

The module uses an MPO/MTP connector interface, which supports multiple fiber strands in a single compact connector. This design is essential for parallel optical transmission, enabling four transmit and four receive channels within a single physical connection.

Energy Efficiency and Power Consumption

Low Power Optical Design

Energy efficiency is a key consideration in modern data center design. The QSFP+ SR4 module is optimized for low power consumption while maintaining high throughput. VCSEL-based optical transmission significantly reduces energy usage compared to older laser technologies.

Impact on Data Center Power Budget

When deployed at scale, power-efficient transceivers contribute to reduced operational costs and improved thermal management efficiency. Lower power draw reduces cooling requirements and supports greener data center initiatives focused on sustainability.

Compatible QSFP+ Modules

Cost Efficiency and Scalability

Compatible optical modules offer significant cost advantages compared to original OEM components. This makes large-scale deployments more economically feasible without compromising essential performance requirements. Organizations benefit from reduced capital expenditure while maintaining high-speed connectivity standards.

Flexibility in Network Expansion

Using compatible modules allows organizations to scale network infrastructure more flexibly. As bandwidth demands increase, additional QSFP+ modules can be deployed without requiring full vendor-specific procurement cycles.