The QSFP+ (Quad Small Form-Factor Pluggable Plus) is a transceiver module used for high-speed network connections, including Ethernet and InfiniBand. The maximum length of a QSFP+ cable depends on the type of cable and the specific technology used. QSFP+ modules can support various types of connections, including direct attach copper (DAC) cables, optical cables, and active optical cables (AOC).

1. Direct Attach Copper (DAC) Cables: These are copper cables with QSFP+ connectors on both ends. The maximum length for QSFP+ DAC cables is typically limited to a few meters, often ranging from 1 to 5 meters.

3. Optical Cables: QSFP+ modules can also support optical connections, where fiber optic cables are used. The maximum length of QSFP+ optical cables can vary based on the type of fiber and the technology employed. For example, multimode fiber (MMF) and single-mode fiber (SMF) may have different maximum lengths. In general, the maximum length for optical cables can range from 100 meters to several kilometers, depending on the specific QSFP+ module and the type of fiber.

It's important to note that the maximum length specifications can vary between different manufacturers and models of QSFP+ modules and cables. Always refer to the specific product documentation or datasheet provided by the manufacturer for accurate information on the maximum cable length supported by a particular QSFP+ module or cable type.