The Small Form-Factor Pluggable (SFP) 3.125 Gigabit Ethernet is a single mode fiber SFP that plugs into a module designed to accept SFPs. The SFP provides a dual optical interface to the 3.125 Gigabit Ethernet physical interface. Installed into an appropriate module, the SFP provides 3.125 Gigabit Ethernet tributary interface to the supporting system.