XFP Optical Modules can only operate in XFP ports, while SFP+ Optical Modules are designed specifically for SFP+ ports. In some cases, SFP+ ports can support standard SFP modules, but XFP ports do not support SFP+ modules. Therefore, direct. The QSFP-DD, QSFP, and SFP transceiver modules are hot-swappable and connect the electrical circuitry of the system with an optical external network. Therefore, direct interchangeability is not possible. Cost and Market. By converting physical form factors and mapping electrical lanes, adapter converter modules let you plug a legacy or lower-speed transceiver into a next-generation switch port. Figure 3-198 shows the structure of an optical module.