The Quad (4-channel) Small Form-factor Pluggable (often abbreviated as QSFP or QSFP+) is a compact, hot-pluggabletransceiver used for data communications applications. It interfaces a network device motherboard (for a switch, router, media converter or similar device) to a fiber optic cable. It is an industry format jointly developed and supported by many network component vendors, allowing data rates from 4x10 Gbit/s. The format specification is evolving to enable higher data rates; as of May 2013, highest possible rate is 4x28 Gbit/s.
The QSFP specification accommodates Ethernet, Fibre Channel, InfiniBand and SONET/SDH standards with different data rate options. QSFP+ transceivers are designed to carry Serial Attached SCSI, 40G Ethernet, QDR (40G) and FDR (56G) Infiniband, and other communications standards. QSFP modules increase the port-density by 3x-4x compared to SFP+ modules.
QSFP has 38 pins with 4 high-speed TX pairs (CML-I) and 4 high-speed RX pairs (CML-O).