xfp

XFP is a high-speed optical transceiver module defined by the XFP Multi-Source Agreement (MSA) for 10 Gigabit Ethernet, Fibre Channel, and other 10 Gbit/s networking applications. Introduced in the early 2000s, XFP modules are designed to be hot-swappable and plug into optical network equipment to provide the interface between host systems and fiber. The form factor is larger than later pluggable standards, and XFPs are commonly used in older equipment or networks that originally adopted the XFP standard.

Technically, an XFP module combines a laser transmitter, a photodetector receiver, and supporting electronics within a compact housing. The electrical interface is a high-speed serial link that typically operates around 10 Gbit/s, while the optical interface uses fiber and a standard LC connector. XFP transceivers support multiple optical wavelengths, most frequently 1310 nm or 1550 nm, with the choice influencing reach over single-mode fiber. The MSA defines the mechanical, electrical, and optical characteristics, along with environmental and safety requirements, to ensure interoperability among vendors.

Diagnostics and monitoring are supported through digital diagnostics monitoring (DDM), commonly implemented via an I2C-based interface (often compatible with SFF-8472). This allows reporting of parameters such as temperature, supply voltage, bias current, and optical power levels, aiding in network maintenance and fault detection.

Applications and legacy status: XFP transceivers were widely used in 10 Gbps networks, including data centers and service provider backbones. Over time, newer and smaller form factors such as SFP+ and QSFP+ largely supplanted XFP in new deployments. Nevertheless, XFP devices remain present in older equipment and networks, and some vendors continue to supply them for compatibility with existing installations.