Hardware manufacturer.

[bsaidus]

Why you don't want to use SFP? When the media changes, you can easily turn it around against gpon, ethernet, etc. ADSL is dead now, VDSL will live for a few more years. The future is ethernet and gpon. The SFP is easily replaceable. (m)pcie sfp cards are available. You can use an itx x86 board and install whatever you want there.

In country where I live (Algeria), there is no other technology then ADSL .

 

[Deleted member 81054]

I want to make an ADSL modem with my specifications (Ex: RAM 4G / STOCKAGE: 20G / CPU: Intel x86_64 / LAN: 4, WIFI, ... ).

Why don't you, instead, figure out how to make a "host" that is small enough that it could be used alongside an off-the-shelf ADSL modem?

The "filtering" you desire could be implemented with a single network interface -- or, dual, if you want to prevent any "leakage" of the unfiltered traffic. You could likely implement just the filter logic with a pruned down OS (perhaps not even FreeBSD) if filtering is all you want to accomplish. This lets you reduce the hardware requirements (cost, size) to better fit the problem.