The QSFP112 (Quad Small Form-Factor Pluggable 112) is a next-generation transceiver that supports data rates of up to 100 Gbps per lane, resulting in a total maximum data rate of 400 Gbps. As of my last knowledge update in January 2022, the QSFP112 is part of the evolving standards to meet the increasing demand for higher bandwidth in data center and high-performance computing environments. 

Whether QSFP112 is backward compatible with previous QSFP generations (like QSFP28, QSFP56, etc.) depends on the specific design and standards adopted by the manufacturer. Generally, the industry has aimed for backward compatibility within the QSFP family to ensure a smooth transition and interoperability between different generations of transceivers and networking equipment.

Key points to consider:

1. Connector Compatibility:

• The physical form factor and connectors of QSFP112 may differ from previous QSFP generations. Backward compatibility in this aspect may require the use of adapters or specific port configurations.

2. Electrical and Protocol Compatibility:

• QSFP112 may use different electrical signaling and communication protocols compared to previous generations. Compatibility in this area would depend on the implementation of industry standards and the specific capabilities of networking equipment.

3. Support for Higher Data Rates:

• QSFP112 is designed to support higher data rates compared to its predecessors. While backward compatibility might be considered, the primary purpose is to leverage the higher speeds enabled by QSFP112.

4. Industry Standards:

• The backward compatibility of QSFP112 would depend on adherence to industry standards. Manufacturers may implement features to ensure compatibility, but it's essential to check the documentation and specifications provided by the equipment manufacturer.

Always refer to the documentation and specifications provided by the equipment manufacturer to determine the backward compatibility of QSFP112 with previous QSFP generations. The networking industry often emphasizes backward compatibility to facilitate seamless upgrades and integration into existing infrastructure.