Hi there,

I just purchased and installed a CRS317, a CRS326, and CRS328. Currently, I'm trying to provision my CRS317 as a core switch/router, and I'm attempting to install a Huawei MA5671A SFP ONT into it for FTTH Internet access. My ISP is Bell Fibe, and I pulled the SFP ONT from the Home Hub 3000 they provided.

When I login to the WebFig interface on the CRS317 (or CRS328), and insert an SFP+ transceiver into a port, I can see the various details of the SFP+ transceiver automatically populate in the interface status for the port (i.e. Vendor, Model, Serial #, etc.).

However, this does not occur when I insert the Huawei SFP ONT, nor does it show the port as being active. I'm relatively new, but when I check the logs, nothing relevant seems to show up.

It seems as though the SFP ONT doesn't physically fit. I slide it in, and I can feel/hear the SFP ONT click into place, but it does not click as well as other transceivers I insert (that do work).

I'm happy to provide more information and perform more diagnostics, but this seems to be my current theory. Any help would be appreciated!

Ok, so I managed to get the SFP to work. Turns out, you need to force it to 1000M by turning off auto negotiation. Furthermore, you need to power down the CRS, plug in the SFP, and then power up the CRS. It might take a few power down/up cycles, but eventually, the CRS will bring the SFP up and it will maintain a link.

Except now, I can't seem to get the PPPoE connection to establish. It looks like I have to set the VLAN to 35, which I believe I've done correctly, but it's still not working. Not sure how to resolve this now.

Ok, so I managed to get the SFP to work. Turns out, you need to force it to 1000M by turning off auto negotiation. Furthermore, you need to power down the CRS, plug in the SFP, and then power up the CRS. It might take a few power down/up cycles, but eventually, the CRS will bring the SFP up and it will maintain a link.

i assume the "link" you refer to on your device, that is the "ethernet link" between your CRS (the sfp socket) and the ONT module (the sfp plugged into the socket) - as this is GPON, which is inherently non-ethernet, you can't see further.
turning off autonego is not a good idea. you can get into situation - most probably you experience it right now - where the router "shows" the link is up, but in general it is not up.

if you don't see anything, most probably you have no "real" link. or the ONT is misconfigured. or your side is misconfigured.
otoh to have pppoe a working pppoe link, you need to talk into the right VLAN (i.e. config on your router) - your operator knows it - and this has to be also configured in the ONT (something you can't do from your router, but only the operator from the GPON side over OMCI. they need to provision it into your SFP-ONT device. and obviously the two shall be corresponding to each other. if any of these two is missing, it won't work.
until you don't send a PADI in the right VLAN, you might not see nothing coming to you from the PPPoE server, as GPON shall isolate endpoints, so you can't see anyone else's frames on ethernet level.

the symptoms you talk about are very similar to the case, when you plug in a non-mikrotik copper SFP to a mikrotik device (we tried it with several vendors' SFPs), and none of them worked properly, contrary to "real" optical SFPs, where i never saw any interop issues with mikrotik [even dwdm-sfp support was added to routeros couple of years ago]. GPON ONU/ONTs in SFP form factors are complex devices compared to regular optical SFPs. most probably routerOS doesn't support the one you have.

talk to support@mikrotik.com, they might be able to fix this in a later release. they solved the dwdm-sfp issue in 2weeks with an RC image after i ran into it and reported it.