My Internet provider just installed a 2,5/1Gbps Internet connection and I’ve asked the guys to run a couple of their fiber to connect my router (HP Prodesk with OPNsense) to my server. I didn’t know that the fiber is single mode and all the SFP+ sold used now seems to be all for multi mode fiber (www.bargainhardware.co.ukfor example). The cable is about 30m, can I use a 810nm SFP+ or is it definitely better to use a 1310nm?

  • @dhorkEnglish
    1•6 months ago

    There definitely are optics available for single mode. The problem is that the wavelength will need to match what you are being sent from your provider. So we can’t really answer your question, you will have to ask them.

    1310nm is quite common but we can’t assume your link is 1310nm.

    • @peregusOP
      2•6 months ago

      I don’t need to connect my provider fiber, but my router (OPNsense) to my server.

      • @dhorkEnglish
        2•6 months ago

        Oh, they just left you some extra patch cables? That was nice of them.

        The wavelength of the fiber might be printed on it. I know some fibers are color-coded based on their wavelength, but I don’t know if it’s universal.

        You’ll need to match the modules to the fiber.

        • @peregusOP
          2•6 months ago

          I’ve checked on a forum and they say:

          GPON adopts WDM to transmit data of different upstream/downstream wavelengths over the same ODN. Wavelengths range from 1290 - 1330 nm in the upstream direction and from 1480 - 1500 nm in the downstream direction.

          So I guess that all the single mode SFP+ that have that range are ok.

        • @peregusOP
          1•6 months ago

          Unfortunately there is no wavelength on the cable, I’ll check the ONT