for reference, I have a Billion 8700VAX with the AC800S tethered via the USB interface and now working (yay!), albeit in NAT mode, rather than being bridged. I'll be giving Billion a call in the morning to see if there's a solution, as the router will pick up an IP address from the modem when it's in bridge mode (IP passthrough), however, the router does not configure a route to the USB interface.
Next is to get an antenna to improve bandwidth.
Will report back with any further progress.
Keep in mind that 4g connection has public IP. so cannot open ports and there will be a double nat issue regardless of how optus ditributes IP's over the 4g network
Not like a dymanic or static IP you get when you have a physical connection, like adsl, cable or nbn
I contacted Billion and they sent me an updated firmware for my 8700VAX, which solved the bridging issue. I now have an AC800S working in IP Passthrough mode on my Billion 8700VAX - I must say Billion have great support, very responsive.
Now that it is up and running, I see what you mean regarding IP Addresses. This does dampen things a little, however I will retain the DSL as a 'backup link' and use it to run, incoming services (VPN) and the Fetch box - which requires the DSL, and run everything else out the 4G.
My bandwidth has gone from 4Mbs to just over 30Mbs by routing out to the 4G interface, and I reckon with an antenna I could probably get closer to 80Mbs as I have line of sight from the roof to a full spectrum Optus tower about 800 metres away. I parked under it the other day with the modem and my laptop and was getting around 85 - 90Mbs - was hoping for more, however, better than 4Mbs. All this just get through, at least, the next twelve months while NBN gets its act together.
Thanks for your input too. If I 'discover' anything else along the journey, I'll report back.
I tired giving the router 192.168.2.25# (it was always at 192.168.1.25#), then couldn't find it and since it's my gateway for devices was just causing endless issues. I reset both devices multiple times.
Finally got it to work but instead of manually setting the usb service to Australia Optus I left on Auto. Also router is where I want it to be e.g. 192.168.1.25#
So far so good with 45Mbp/s - 60Mbp/s and Netflix streaming nicely. Only thing is this optus crowd site doesn't load properly after a long load time :S had to post this via mobile data.
This is axactly what I want to do - to keep my RT-AC66U router as 192.168.1.25* as I have dozens of devices running off of it and don't want to have to change the whole network.
Did the AC800S eventually change its IP range to something other than 192.168.1.25* ?