said by netcool :

That used to be a big problem with Pre-DOCSIS CMTS.

Now with DOCSIS all packets are encrypted back to the CMTS using BPI.

There are also cable filters in place on the CMTS.

»noc.caravan.ru/ciscocd/cc/td/doc···xtocid18

said by swintec :

This was always the case back when we had Adelphia. Then one morning when Time Warner did the cut over to there system and took control of the modems, instead of baseline privacy saying "Done" it said "Skipped"...I do not know what TW uses in place of BPI, but i always found it odd as to why they do not use it.