I want to find a GPON router for OpenWRT. But on the site I could not find any gpon router model on which you can install openwrt
Tell me please, am I looking badly, or is it impossible to put free firmware on GPON routers for some other reason?
one option would be to pick a openwrt compatible router with sfp port (like turris omnia) and plug a sfp-gpon there (google it) - this is what it worked for me 1 year ago but it wasn't officially supported by my ISP and unstable (link stopped and needed isp device to work again) so I rolled back to their solution as I needed a stable connection.
Keep in mind that SFP-gpon firmware is not free so maybe not exactly an answer for you.
And you should also check with your ISP if they officially support you using your own device or might face issues like I did and be on your own.
oh and remember that classic analog services like CATV or fixed PHONE won't work unless the ISP provided over IP (IPTV,VoIP, etc) and you'll need to configure your own VLANs etc...
GPON routers are usually provided for free by the ISP. To reduce the cost, while maintaining complete control of the device, they usually request the OEM to make a customized device with a strange model number. As long as the number of devices is large enough to worth their effort, the OEM will do.
We, as the end users, are given customized boxes which are not available for retail sale. These devices are also available for a limited time, until the ISP finds a better deal with another OEM.
If no one is interested in porting OpenWrt to such device, then it is simply not available. Even Chinese crypto mining routers have OpenWrt -- some have official support, some only have unofficial ports, or variations (X-Wrt).
Your best option is to use your ISP box as a optical to Ethernet bridge.
Technically there is no real difference between a proprietary ONT in its own case, connected via ethernet - or an equally proprietary ONT in SFP form factor, the later is just smaller and more prone to overheating (and harder to upgrade). In either way, the ISP has to accept it, either formally or you by faking the serial of the ISP's original one.
In my case faking was not enough as after some random no of days it just stopped working and needed original device connected then back with the faking. Not something you want to do...