SFP EEPROM programing

Level1Techs INBOX.deb
1

Good morning.

So where to start with this.

I live in Spain, and our FTTH coverage here is amazing, specially where I live in Madrid. There is also very good options for provider, I can get up to 1 GB service with no less than 5 different providers and it is cheap, but enough bragging about the good, now for the bad, ZTE and Huawei ONT+Router combos are all that is used. Obviously there are a number of reasons to get this device out of my pathway to the internet, but they don’t make that easy.

ZTE on the other hand is married to the SMB 1.1 protocol for USB sharing, and it is possible to trigger a memory dump to retrieve the credentials needed to configure an ONT. I have successfully configured a Ubiquity Ufiber LOCO ONT with the Huawei profile to allow access directly from my PFsense router to the internet. This may be enough for a normal person, but I have never been accused of being normal. This can be validated by my religious following of Level1tech news.

Joking aside, the next logical step would be to remove the Ubiquity ONT and connect the Fiber cable directly to the PfSense router. This could in theory be achieved by installing an SFP card, and using the appropriate SFP to communicate with the fiber network. To my knowledge the provider provisions the GPON based on S/N:.

So my initial approach was to get a Huawei GPON SFP, and a Reveltronics EEPROM programmer. The Idea was to change to Vendor Model, and SN to match that of my original, ZTE router. Plug it into the SFP card, into the Fiber, let the magic happen, make a sweet YouTube video about it and call it a day. Like many of my little tech projects, it did not work that way. Changing the SFP info was simple enough, but it simply did not work.

Really I am way out of my league on this, I have so little knowledge on this level of networking, I am not even sure where to look for more information. And it seems what I am trying to do is such a specific case there are simply not a lot of people trying to do this.

With all of that the help I am looking for is where I can go to be better educated on configuring SFPs. For example I would like to know if there is a way I can access the SFP from a command line in PfSense, and/or configure the credentials manually. Or what I might edit and write in the EEPROM. I need more information about what is going on there.

Thank you

The setup.
(Current)

  • “Router” currently a Wyse thinnet client with Intel Dual gigabit Ethernet adapter running PfSense.
  • ONT Ubiquity Ufiber Loco set to Huawei profile.
    (Planned)
    -SFP adapter Chelsio N320E-SR (B)
    -ONT GPON-ONU-CLASS B+I RTXM 167-431

-EEPROM programmer Reveltronics revelprog IS with SFP 2line adapter.

-Fiber provider MasMovil/ Yoigo but I am not married to it, should switch be required to achieve my goal.

2

May be a dumb question, but have you actually tried connecting your own SFP-equipped router to the network as is?

Also is the ISP using actual SFP/removable transceivers or are they integrated into the router?

I’m asking because where I am, I can swap routers as I see fit. The only difference is in the SFP transceivers themselves.

3

My ISP does not use SFP. They use Integrated ONT+Router (in this case ZTE F680) when it is connected to the network the OLT configure the GPON automatically. The ZTE routers use SMB 1.1 for sharing USB devices, which is easy to exploit, and there is a well known exploit where with the creation of a Symbolic link to Ifconfig one can inject commands with SU permission. This can be used to dump the memory to a file, and that file contains the GPON password. With that it is possible to configure a standalone OLT to communicate with the fiber network.

That is how I was able to use the Ufiber Loco in bridge mode to use the router I have now.

I have tried installing the SFP adapter and GPON SFP but It does not seem to work, it seems the OLT has not configured the SFP as planned. I am wondering if the OLT has to be told to configure the GPON or if it would initiate this process automatically when it detects an in configured device, or if the GPON needs to request configuration. Like I said I don’t know much about what happens between the fiber cable coming into my home and what it connects to on the other end.