cyril7:
Should point out that in my case the modem is approx 10m of cable from the ISAM, we have one in one of our server rooms. As for 30a/35b as Atomeara said, only 8b/17a is supported.
Cyril
only 17a when vectored too.
i forget which of 30a or 35b aligns to 17a but they again would need to have specifically the right bandplan.
Overall though, the gains to hardware cost is likely too high.