QSFP+ (Quad Small Form Factor) is a hot-swappable transceiver. QSFP+ represents a further development of the SFP+ transceiver and can replace four SFP+ transceivers with 4x 10G channels. This leads to a higher port density and thus savings in the overall system.
With the introduction of 100G, the next generation step to QSFP28 was laid. With four separate 25G channels, QSFP28 can be used in 100G networks. In a breakout cable version, it can even be combined with four SFP28 transceivers.
QSFP56 was released in 2017 and represented a significant design advance over previous QSFP modules. The QSFP56 module is designed to support 200G Ethernet. It is equipped with four transmit and receive channels, each capable of operating at 53.125 Gbps, for a combined total data rate of 212.5 Gbps.
850 nm, 1,310 nm, CWDM or LWDM wavelengths are used for data transmission. MPO or LC connectors are used as the optical interface and a 38-pin connector as the electrical interface. In contrast to earlier QSFP form factors, the digital modulation scheme PAM4 is used.
The next level is reached with the QSFP112 module. It complies with the latest QSFP112 MSA specification and supports 112G-PAM4 electrical and optical signaling. Four transmit and receive channels each transmit 106.25 Gbit/s, achieving a total data rate of 425 Gbit/s.