Is that possible to use duplex SFP which will send and receive signals over only one fiber in backbone? Please refer to the picture.

If so, then how the termination of patchcords and backbone's fiber is happened?

What kind of socket it is used inside ODF? if possible attach a pic.

Or in this case it should be 2 fibers used on the backbone.

Thank you beforehand. enter image description here


1 Answer 1


If you refer to a single fiber strand you'll need an SFP module supporting "BiDi" fiber - 1000BASE-BX(10), 10GBASE-BR/"-BX" or similar. Single strands are also used for shared fiber architectures, most prominently GPON, where you require active termination of the fiber (an ONT).

While it is possible to optically multiplex a (perhaps more common) dual-strand Ethernet variant onto a single strand, requiring wavelength conversion, it usually isn't cost effective. In any case, if the other side is already terminated you'll need to match the SFP module to its physical-layer variant.

Optical connectors vary. The most common kinds:

LC duplex connector (high density, most common) LC duplex connector (used on SFP modules, high density, most common)

SC duplex connector (still common) SC duplex connector (still common)

two ST connectors (legacy)

Pair of ST connectors (legacy)

For a more complete list, see Wikipedia.

  • Thank for your answer. Sorry but this not what I was asking for.
    – A M
    Commented Jan 25, 2022 at 13:40
  • I'm afraid your question is rather unclear then. If the handover out of ODF is duplex fiber you'll need a duplex SFP, and if there's no conversion from single strand inside ODF you'll need a bidi SFP (using wavelength-division duplex). In any case you'll need to investigate the used protocol (1000BASE-LX, 1000BASE-BX10, 10GBASE-LR, ...) and match your SFP.
    – Zac67
    Commented Jan 25, 2022 at 14:17
  • I got you, thanks. Now I would like to understand if sockets(inside ODF) for this design are exist. Like I have drafted on the attached pic. 2 <-> 1
    – A M
    Commented Jan 26, 2022 at 5:23
  • A kind of those "three-way connectors" are optical multiplexers (for different wavelengths, used with WDM) or splitters (for same wavelengths, used with PON) - neither does what you (seem to) want. You need to find out the protocol that is used and report back.
    – Zac67
    Commented Jan 26, 2022 at 6:56

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