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    SFP28 and SFP+ Optics Compatibility

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    • T
      tman222
      last edited by

      Hi all,

      Looking for some help understanding the compatibility of different optics. What is the backward/forward compatibility between SFP28 and SFP+? More specifically:

      1. Generally speaking, can a SFP+ transceiver be used in a SFP28 cage to establish a 10Gbit link?
      2. Generally speaking, can a SFP28 transceiver be used in a SFP+ cage to establish a 10Gbit link?

      When trying to establish a 10Gbit link between an SFP28 port on one side (e.g. server) and SFP+ port on the other side (e.g. switch), is it recommended to use a 10/25Gbit dual rate SFP28 transceiver in the SFP28 port, or would it also be ok just to use SFP+ transceivers on both sides (i.e. server and switch)?

      Thanks in advance for the help and explanation.

      keyserK Dobby_D 2 Replies Last reply Reply Quote 0
      • keyserK
        keyser Rebel Alliance @tman222
        last edited by

        @tman222 said in SFP28 and SFP+ Optics Compatibility:

        Hi all,

        Looking for some help understanding the compatibility of different optics. What is the backward/forward compatibility between SFP28 and SFP+? More specifically:

        1. Generally speaking, can a SFP+ transceiver be used in a SFP28 cage to establish a 10Gbit link?
        2. Generally speaking, can a SFP28 transceiver be used in a SFP+ cage to establish a 10Gbit link?

        When trying to establish a 10Gbit link between an SFP28 port on one side (e.g. server) and SFP+ port on the other side (e.g. switch), is it recommended to use a 10/25Gbit dual rate SFP28 transceiver in the SFP28 port, or would it also be ok just to use SFP+ transceivers on both sides (i.e. server and switch)?

        Thanks in advance for the help and explanation.

        Generally SFP+ trancievers will work just fine i SFP28 cages as that has been designed as backward compatible. However - SFP+ tranciever interoperability with the OS owning the cage is required as always (firmware/device support). But the cage has full technical SFP+ support.

        The other way around - SFP28 tranciever in a SFP+ cage is hit’n miss. Technically they fit, and technically there is nothing to prevent it from working - BUT: The SFP28 tranciever needs to support operations in SFP+ backward compatibility mode, and after that comes the whole OS support of the cage owner. So don’t count on it, but within a vendors portfolio there is quite often support for their own trancievers.

        Love the no fuss of using the official appliances :-)

        1 Reply Last reply Reply Quote 0
        • Dobby_D
          Dobby_ @tman222
          last edited by

          @tman222

          Generally speaking, can a SFP+ transceiver be used in a SFP28 cage to establish a 10Gbit link?

          This should be running if there will be no "vendor check"
          and "firmware blob" in game. Some vendors do this check
          and won´t play nice together with other vendors equipment.

          Generally speaking, can a SFP28 transceiver be used in a SFP+ cage to establish a 10Gbit link?

          Like @keyser said, with some luck it would be running
          but I would not count on.

          #~. @Dobby

          Turris Omnia - 4 Ports - 2 GB RAM / TurrisOS 7 Release (Btrfs)
          PC Engines APU4D4 - 4 Ports - 4 GB RAM / pfSense CE 2.7.2 Release (ZFS)
          PC Engines APU6B4 - 4 Ports - 4 GB RAM / pfSense+ (Plus) 24.03_1 Release (ZFS)

          1 Reply Last reply Reply Quote 0
          • T
            tman222
            last edited by

            Thanks @keyser and @Dobby_ for the explanations, I really appreciate it. If the goal is to achieve a 10Gbit link between SFP28 on one side and SFP+ on the other, do you think I would have better luck trying an SFP+ transceiver in the SFP28 cage, or going with a dual rate 10/25Gbit SFP28 receiver instead, assuming that the underlying controller on the SFP28 side supports 10Gbit operation? Thanks again.

            Dobby_D keyserK 2 Replies Last reply Reply Quote 0
            • Dobby_D
              Dobby_ @tman222
              last edited by

              @tman222 said in SFP28 and SFP+ Optics Compatibility:

              think I would have better luck trying an SFP+ transceiver in the SFP28 cage, or going with a dual rate 10/25Gbit SFP28 receiver instead,

              What hardware is there present, would be nice to know
              for us. Don´t take me wrong here at this point, but it is
              mostly not able to guess what is running out of the box
              and what not! An example:

              HPE Proliant Microserver gen. 10 (Intel Xeon E3-1231v3)
              32 GB RAM / 4x 4 TB SSD WD RED

              • with a dual SFP+ cards (HPE) sorted and together
                with a QNAP Switch all was running out of the box
                with SFP+ optics.

              • with a dual SFP28 card (HPE) sorted and together
                with another switch I don´t know anymore and the
                same SFP+ optics it was not running!

              So it is not so easy to tell others what do do or go with!

              #~. @Dobby

              Turris Omnia - 4 Ports - 2 GB RAM / TurrisOS 7 Release (Btrfs)
              PC Engines APU4D4 - 4 Ports - 4 GB RAM / pfSense CE 2.7.2 Release (ZFS)
              PC Engines APU6B4 - 4 Ports - 4 GB RAM / pfSense+ (Plus) 24.03_1 Release (ZFS)

              T 1 Reply Last reply Reply Quote 0
              • T
                tman222 @Dobby_
                last edited by

                @dobby_ - thanks again for the help. It was mainly a hypothetical question for now to understand the limitations I might be running into.

                1 Reply Last reply Reply Quote 0
                • keyserK
                  keyser Rebel Alliance @tman222
                  last edited by

                  @tman222 said in SFP28 and SFP+ Optics Compatibility:

                  Thanks @keyser and @Dobby_ for the explanations, I really appreciate it. If the goal is to achieve a 10Gbit link between SFP28 on one side and SFP+ on the other, do you think I would have better luck trying an SFP+ transceiver in the SFP28 cage, or going with a dual rate 10/25Gbit SFP28 receiver instead, assuming that the underlying controller on the SFP28 side supports 10Gbit operation? Thanks again.

                  It should be even steven as the only “limiting” factor in that setup is if the SFP28 Cageowner OS supports the tranceiver you intend to use (either the 10/25 SFP28 or the 10G SFP+).
                  The cage specifications supports both operational scenarios from a hardware perspective.

                  Love the no fuss of using the official appliances :-)

                  1 Reply Last reply Reply Quote 0
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