QSFP+ (Quad Small Form-factor Pluggable Plus) is a type of high-speed, hot-pluggable transceiver module used in data communication applications. It is designed to support data rates of up to 40 gigabits per second (Gbps). Here are some common uses of QSFP+ modules: 

1. 40G QSFP+
   

2. 40 Gigabit Ethernet (40GbE): QSFP+ modules are often used in networking equipment to enable high-speed data connections in 40GbE networks. They provide a compact and efficient solution for transmitting and receiving data at 40Gbps speeds.

3. InfiniBand Connectivity: QSFP+ modules are used in InfiniBand networks, providing high-performance interconnects for high-speed computing and storage systems.

4. Data Center Interconnects: In data centers, QSFP+ modules are employed to establish high-bandwidth connections between switches, routers, and other networking equipment. They contribute to the overall efficiency and speed of data transfer within the data center environment.

5. High-Performance Computing (HPC): QSFP+ modules are commonly used in HPC environments where fast and reliable communication between computing nodes is essential for parallel processing and scientific computing applications.

6. Fiber Channel Applications: QSFP+ modules can be used in Fiber Channel environments, providing high-speed connectivity for storage area networks (SANs) and other storage applications.

7. Backbone Networks: QSFP+ modules are suitable for building backbone networks that require high bandwidth and low-latency connections. They help facilitate the transfer of large amounts of data between different parts of a network infrastructure.

8. Telecommunications: In telecommunications networks, QSFP+ modules can be used to support high-speed data transmission, contributing to the development of faster and more efficient communication networks.

It's important to note that while QSFP+ supports data rates up to 40Gbps, newer standards like QSFP28 have been introduced to meet the demand for even higher data rates, supporting up to 100Gbps. The specific application of QSFP+ modules depends on the networking requirements and the equipment they are being used in.