Features: 1) The 1000BASE-BX-D and 1000BASE-BX-U SFPs are compatible with the IEEE 802.3ah 1000BASE-BX10-D and 1000BASE-BX10-U standards, operate on a single strand of standard single-mode fiber 2) A 1000BASE-BX10-D device is always connected to a 1000BASE-BX10-U device with a single strand of standard single-mode fiber with an operating transmission range up to 10km 3) The communication over a single strand of fiber is achieved by separating the transmission wavelength of the two devices as depicted in figure 2; 000BASE-BX10-D transmits a 1,490nm channel and receives a 1,310nm signal, whereas 1000BASE-BX10-U transmits at a 1,310nm wavelength and receives a 1,490nm signal