Sometimes the optical module is replaced by an electrical interface module that implements either an active or passive electrical connection to the outside world. This is used when the link is short, particularly when connecting to a top of rack switch. OverviewAn optical module is a typically hot-pluggable optical transceiver used in high-bandwidth data communications applications. Optical modules typically have an electrical interface on the side that connects t. There have been multiple variants of the electrical interface of optical modules that have been used over the years. The earliest forms of optical modules had an analog electrical interface. In the transmit dir.