Hi Stuart,
I guess my question here is does anyone know if this can be done legally within the terms of any contract?
The FTTC/VDSL2
modem supplied by BT is usually a Huawei HG612 (one or two other different BT supplied modems have recently been noticed).
As Walter mentions, this HG612 modem is completely locked from end user access.
The modem is part of BT's equipment & remains so.
Unlocking firmware has been successfully developed that allows full access to the modem's statistics.
However, the use of such an unlocked modem will no doubt be in complete contravention of BT's terms and conditions of use.
A user may connect any router of choice to the HG612 modem.
I believe BT Infinity users are provided with a Home Hub router.
My own ISP provided me with a Netgear WNR 1000v3 router, for connection to the HG612 modem.
Other VDSL2/FTTC modems can be purchased (at great expense - £200 or so), but they do not appear to provide any improved performance over the HG612, & again, the use of such a modem would no doubt be in breach of BT's Ts & Cs.
Spare and/or unlocked HG612 modems are available via ebay, apparently at "reasonable" prices.
However, strictly speaking they are actually the property of BT, so I'm not quite sure how legal the sale of them will be.
If any modem other than the supplied & locked HG612 is used, I would imagine that BT could simply refuse to deal with any connection "faults" as they could argue that non-supplied & non-approved equipment is being used.
Notwithstanding the above comments, I believe it is a very quick & simple task to restore the HG612's original firmware, thus restoring it to its "as provided" condition.
Paul.