Single-fiber bidirectional QSFP-DD transceivers provide 100Gbps full-duplex connectivity over a single optical fiber, enabling efficient high-speed network deployment in India.

Overview of Single-Fiber Bidirectional QSFP-DD

Single-fiber bidirectional (BiDi) QSFP-DD modules, such as Cisco QSFP-100G-B20U4-I/B20D4-I and NEC 100G QSFP28 BiDi, allow 100Gbps full-duplex transmission over a single SMF (Single Mode Fiber), reducing fiber usage and cabling complexity . These modules operate using multiple wavelengths in opposite directions, enabling simultaneous transmit and receive signals on the same fiber. Cisco modules use four transmitters and receivers muxed via a diplexer filter, supporting distances up to 20 km, while NEC BiDi modules can reach up to 80 km using LWDM technology .

Technical Features

• Form Factor: QSFP-DD or QSFP28, compatible with high-density 100G ports .
• Wavelengths: Typically four wavelengths spaced in the O-band or LWDM band for bidirectional operation .
• Modulation: NRZ for Cisco modules; PAM4 may be used in some QSFP28 variants .
• Fiber Type: Single-mode fiber (SMF) for long-distance links; multimode fiber (MMF) for short-reach BiDi modules like 40G QSFP-BD .
• Power Efficiency: Low-power design suitable for data center and enterprise core networks .

Use Cases

• Data Center Interconnects: High-speed links between racks or aggregation switches.
• Enterprise Core Networks: Efficient 100G connectivity without additional fiber deployment.
• Telecom and Service Providers: Long-distance 100G links with reduced fiber infrastructure.
• Network Upgrades: Replacing 10G/40G links while minimizing fiber consumption .

Procurement Options in India

• Cisco QSFP-DD Modules: Available through authorized Cisco distributors and partners in India, supporting 20 km SMF links .
• NEC 100G QSFP28 BiDi: Can be sourced via NEC India or authorized resellers, suitable for up to 80 km SMF deployment .
• FS QSFP28 Modules: FS offers certified 100G QSFP28 transceivers compatible with Cisco, Arista, Juniper, and Brocade, available for Indian procurement .
• Local Suppliers: Companies like Commando Networks in Navi Mumbai provide optical transceivers, including QSFP+ and BiDi modules, for enterprise and data center applications .

Considerations for Procurement

• Compatibility: Ensure modules are compatible with existing switches and routers.
• Distance Requirements: Choose modules based on link length (20 km vs 80 km).
• Fiber Availability: Single-fiber BiDi reduces fiber usage, ideal for limited fiber infrastructure.
• Vendor Support: Prefer authorized distributors for warranty, support, and compliance with Indian import regulations. By selecting single-fiber bidirectional QSFP-DD modules, Indian enterprises and service providers can achieve high-speed 100G connectivity with reduced fiber deployment, improved network resiliency, and cost efficiency.