Generic Compatible 100GBASE-SR2 QSFP56 2x50G PAM4 850nm 100m MMF DOM MPO-12/APC Optical Transceiver Module

Q56-100G-SR2-A: Frequently Asked Questions

Q: What applications is the Q56-100G-SR2-A module designed for?

A: The Q56-100G-SR2-A is designed for short-reach, high-speed optical interconnects in data centers. It supports 100G connectivity over multimode fiber and can be deployed in 200G QSFP56-based network environments where supported by the host platform. When paired with compatible 200G QSFP56 SR4 equipment, it can support flexible network configurations, including 200G-to-2×100G connectivity, subject to the switch and port breakout capabilities.

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Q: What is the difference between QSFP56 100G SR2 and QSFP28 100G SR4?

A: The primary differences are the modulation format and lane configuration. QSFP28 100G SR4 typically uses four 25Gbps NRZ lanes, whereas QSFP56 100G SR2 uses two 50Gbps PAM4 lanes to achieve an aggregate data rate of 100Gbps. The SR2 design provides higher per-lane bandwidth and a two-lane architecture, which can simplify lane mapping in compatible network environments. Despite sharing a 100G aggregate data rate, the two module types are not directly interchangeable.

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Q: What are the key technical specifications of the Q56-100G-SR2-A?

A: The Q56-100G-SR2-A uses PAM4 modulation with two 50Gbps lanes to deliver an aggregate data rate of 100Gbps. It is designed for short-reach transmission over multimode fiber. The supported transmission distance depends on the fiber grade and the module’s validated specifications; OM4 fiber may support distances of up to approximately 100 meters in suitable implementations. Please refer to the product datasheet for the exact reach and supported fiber types.

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Q: Can the Q56-100G-SR2-A operate in a 200G QSFP56 port?

A: It may operate in a 200G QSFP56 port if the host device supports the module, its identification and operating mode, and 100G link operation. Physical form-factor compatibility alone does not guarantee interoperability. Before deployment, verify the switch or adapter’s supported transceiver list, port configuration, and firmware requirements. When supported, the connection operates at 100Gbps rather than 200Gbps.

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Q: Can the QSFP56 100G SR2 interconnect directly with a QSFP28 100G SR4 module?

A: Direct interconnection should not be assumed. The QSFP56 100G SR2 uses two 50Gbps PAM4 lanes, while the QSFP28 100G SR4 typically uses four 25Gbps NRZ lanes. Their optical lane configurations and signaling formats differ, so a direct link generally requires compatible optical interfaces and host-side support that explicitly enables interoperability. For reliable deployment, use matching transceiver types or a validated interconnection solution.